Place where dot executable is found

In the current vhdl part of the code it is required that the dot executable is in the path. On in dot.cpp the possibility exists that the dot executable is found through the configuration setting DOT_PATH.
This patch makes this more consistent

Merge branch 'feature/html_entities' of https://github.com/albert-github/doxygen into albert-github-feature/html_entities

On windows citelist.doc remains

On windows the file citelist.doc is not removed as it is not closed. This patch closes the file.

sqlite3 updates

+  -I <I>    Get the includers of <I>
+  -i <I>    Get the includees of <I>
+  -M <C>    Get all members of class <C>
+  -B <C>    Get the base classes of class <C>
+  -S <C>    Get the sub classes of class <C>
Signed-off-by: Adrian Negreanu <adrian.m.negreanu@intel.com>

* template and function arguments
* innernamespaces
* put sqlite3_stmt and the coresponding query in
  a struct
* use has(Multi|One)LineInitializer instead of hardcoded value
  when extracting references from initializers
* sqlite3_clear_bindings in step()
* getRow in step() should use different sqlite3_ functions
  depending on wether is doing 'INSERT' or 'SELECT'

includes table uses only file IDs
Signed-off-by: Adrian Negreanu <adrian.m.negreanu@intel.com>

In doxygen a limited number of HTML4 special character entities are recognized, with this patch the full list of HTML4 special character entities (see http://www.w3.org/TR/html4/sgml/entities.html) is supported (as far as they can be represented in the output format).

- doxygen_manual.tex
- latexgen.cpp
  Added wasysym package to support per thousand sign (perthousand command from textcomp didn't work properly)
  Added option for textcomp package so currency symbol would work properly

- htmlcmds.doc
  Adjusted documentation, listing all entities

- compound.xsd
- xmlgen.cpp
  Removed in xsd file all references for special HTML4 character entities and placed placeholder so doxygen (in xmlgen.cpp)can automatically add the right element names.

- util.cpp
- util.h
  Define all entities with their representation for all output formats.
  Define access routines to the different representations
  Mapping (for recognition of the entities) based on running through the list of available entities, after validation of the order of the entities. A few entities contain now besides letters also numbers at the end.

- docparser.h
  Define symbols for all entities as well as a helper struct and enum. The member m_letter is not used anymore and thus removed.
  All existing symbols were renamed so no confusion (i.e. errors when forgetting to rename some symbols) can occur.
  Obsolete references to letter removed, all letters with accents etc. are explicitly defined and not through the generic accent name plus an extra letter.

- docparser.cpp
  Adjust used symbols to their new names.
  Remove references to letter (as used for accents etc.)
  Replace list of explicitly supported entities with call to symbol code access routine.

- docbookvisitor.cpp
- htmldocvisitor.cpp
- latexdocvisitor.cpp
- mandocvisitor.cpp
- perlmodgen.cpp
- printdocvisitor.h
- rtfdocvisitor.cpp
- textdocvisitor.cpp
- xmldocvisitor.cpp
  Replace list of explicitly supported entities with call to access routine and use returned value to output.

Bug 723299 - Last line of code block lost if it is only one character and there is no text afterward

detect python2 as Python 2 binary

On some distributions like Arch Linux
"python" is Python 3 and "python2" is Python version 2.

We now try "python2" first and use it if available.

Add extra (documenation) directories to ignore pattern

Better message in case doxygen -u is used

Error message is given for make distclean as generated_src is a directory

In case of obsolete or not configured entries in the Doxyfile and the option -u is used a message like:
  Warning: Tag `XML_DTD' at line 1821 of file Doxyfile has become obsolete.
  To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u"
appears, but the item is removed from the Doxyfile.
This patch updates the message (and improves layout) to:
  Warning: Tag `XML_DTD' at line 1821 of file `Doxyfile' has become obsolete.
                  This tag has been removed.

Add docbook directory to be removed as well

Add extra (documenattion) directories to ignore pattern

generated_src is a directory and should be removed with the -rf flag.
Similar for other directories like bin, objects, lib, html latex, objects.
Directories man, rtf, perlmod, xml have been added for convenience (when testing with other documentation formats)

Items XML_SCHEMA and XML_DTD declared obsolete

The items XML_SCHEMA and XML_DTD are not used and there is no plan for using them, so declared obsolete.

Merge branch 'wip/fix-link-id-on-last-line' of https://github.com/agateau/doxygen into agateau-wip/fix-link-id-on-last-line

Conflicts:
	testing/055/md_055_markdown.xml
	testing/055_markdown.md

In the chm-doxygen manual we see that for:
- the command \& the & is missing
- commands containing a " all text is missing after this "
These are known limitations of the chm format (see e.g.
http://www.helpware.net/htmlhelp/hhwreadme.htm)

Ids created from the last line were not lower-cased, leading to the link
not being recognized.