Fixed a minor issue when creating a netlist. for nets having global labels, global label names were ignored when naming this net.

inches and mm, the industry is crazy enough to force us with mixed
design. For example I routinely use imperial units for track size and
clearance, but drilling is strictly a metric issue...

So I added a little parser to recognize a suffix specification in the
unit text boxes... so you can put in things like:
1in (1 inch)
1" (idem)
25th (25 thou)
25mi (25 mils, the same)
6mm (6 mm, obviously)

The rules are: spaces between the number and the unit are accepted, only
the first two letters are significant.

As a bonus, it also recognize the period (.) as a decimal point
substituting it with the correct locale character (there was a wishlist
for it, IIRC). Most useful for number pad fans :D 

dialog_edit_component_in_schematic: moved "Reset to Library Default" Button. This command is now undoable.

fixed bug 603481. Better bitmap2component look. fixed some locate problems for footprints using polygons (mainly created by bitmap2component)

Cleaning code: moved some help strings used both in toolbars and menus in a single file help_common_strings.h,
in order to avoid slightly different help strings for the same command, and avoid some not needed  translations.

* Continue component library class clean up and encapsulation work.
* Change hierarchical sheet label container to boost::vector_ptr.
* Encapsulate hierarchical label handling in hierarchical sheet class.
* Convert some missed occurrences of wxString::GetData() to GetChars( wxString ).
* Fix some minor code formatting issues.

    In netlist generation, changed the rule to calculate netnames of nets with labels:
    Previously, named nets (i.e. nets with local, hierarchical or global labels) have their name
    defined by the first label found in list.
    So net names could be changed without really changing the schematic.
    Now the names are calculated from the rules (by priority order) :
    1 - use the most top level labels in hierarchies.
    2 - use global labels first, local labels next (hidden power pins names are global labels).
    3 - use alphabetic sort (so, if GND and AGND are connected, the net will be always named AGND,
    and adding a VSS connection cannot change the net name)
    So power nets and nets that have more than one label cannot have their netname changed
    if there is no actual change relative to these nets names in schematic

factor some pioneering code into a the stable building block class DSNLEXER, generalize expected valued for name and value within the template field parser.

* Field match method expected SCH_SHEET_PATH pointer type not SCH_SHEET
  pointer type.

Added an experimental tool to create logos from .bmp bitmaps. Added Potrace library to convert bitmaps to polygons

* Fix a minor problem with wxFileDialog to open a file that no longer
  exists in PCBNew.
* Make GerbView open file behavior the same as PCBNew.
* Remove redundant PCB file wild card definition.
* Add open file refactor task to the todo list.
* Fix some minor code formatting issues.

Eeschema: fixed bug 577083. Also fixed a bad import of predefined fields when loading a component from a library, when this component has some empty fields like footprint and documentation but have user fields not void.

* Removed redundant empty string test, thanks again Alain.
* Minor code cleaning.

* Add Bazaar ignore file to ignore files generated by CMake scripts.
* Fixed bug when compiling for Windows agaist shared wxWidgets library.

* Add CMake script to generate DSN token header and source file from
  token list file.
* Add preliminary component library DSN token list and lexer file to
  test script and prepare for new component library file lexer.
* EESchema: right click on ERC check mark displays error in message panel.
* Remove PCBNew header file dependency from common DSN lexer source.
* Minor code clean ups.