Support language switch for language ids, 'Japanese-en', 'Korean-en', 'Serbian-Cyrillic', and similer langauge ids.

This patch adjusts some problems regarding image sizes in LaTeX output of doxygen (a.o. Bug 738299 - When using msc or PlantUML, the default latex for the created image should include [width=\linewidth]) this has been done is such a way that all the "image" commands (i.e. image, dot, dotfile, msc, mscfile, diafile, startuml) operate in a similar way / have the same possibilities.

- commands.doc
Adjusted documentation to reflect changes.

- cmdmapper.cpp
- cmdmapper.h
Added utility function to map command id back to command name

- doctokenizer.h
- doctokenizer.l
Handle Caption  and Size indication. Required also that some other rules had to be tightened a bit (like usage of {} in startuml and usage of "" for captions. This was already described in the documentation in this way).

- docparser.cpp
- docparser.h
Created routine to uniformly handle the Caption and size indications and store them in a general way.

- latexgen.cpp
Replaced graphicx package by adjustbox package (includes graphicx) to support "min width" etc.

- doxygen.sty templates\latex
Added commands to make commands with and without caption behave similar.

- docbookvisitor.cpp
- docbookvisitor.h
- htmldocvisitor.cpp
- latexdocvisitor.cpp
- latexdocvisitor.h
- printdocvisitor.h
- xmldocvisitor.cpp
Created routine to uniformly handle the Caption and size indications in a general way.

- indexpage.xml (testing\022)
- indexpage.xml (testing\031)
- class_receiver.xml (testing\037)
- class_sender.xml (testing\037)
Adjusted example output.

--HG--
extra : rebase_source : aedb08ea08b1b0a983e31a11765c75b56c0b5ceb

--HG--
extra : rebase_source : f516669986006db5aca6af6417f323e57fa848d1

--HG--
extra : rebase_source : 5d7e3a2b3c549419c672cddd8d780542053d68bb

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

This verifies the 'memberdef' table against the generated XMLs.
It accomplishes this by executing a sql query, constructed by iterating
through the children and attributes of the memberdef XML element.

The information translated from xml to sql, is then removed from the DOM,
and the unprocessed bits are printed as warning messages.

usage:
    testing/testsqlite3.py -d /.../doxygen_sqlite3.db -x /.../xml/test__x11_8cpp.xml

output:
WARNING: 'location' has unprocessed attr 'bodyend'
WARNING: 'memberdef' has unprocessed child elem 'briefdescription'
WARNING: 'memberdef' has unprocessed child elem 'detaileddescription'
WARNING: 'memberdef' has unprocessed child elem 'inbodydescription'
WARNING: 'memberdef' has unprocessed child elem 'location'
WARNING: 'memberdef' has unprocessed attr 'kind'
WARNING: 'memberdef' has unprocessed attr 'prot'
WARNING: 'memberdef' has unprocessed attr 'static'
WARNING: 'memberdef' has unprocessed attr 'id'