fixed others very minor bugs.

* 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.

Fixed bugs 2981754 and 2981759 (PCBnew crash when trying to add a new net name to a pad) Linux specific, and perhaps due to a bug in wxGTK 2.8 (does not happen in 2.9)

of the S_SEGMENTs were not all the same, the specctra PATH points would 
come out wrong.

Fixed a bug in search function in Eeschema: search for a component reference in a complex hierarchy was broken

Pcbnew: Fixed an issue in GERBER file creation, under Vista and W7 only for non administrator users
Plot files were 0 byte length.
This was due to use of function tmpfile() in a GERBER function to create a temporary file that seems not working using mingw.
Replaced by more usual files functions.

Eeschema: fixed some issues in undo/redo and ESC commands related to hierarchical sheets; Work in progress

Grid list display in popup menu: go back to the previous version, due to problems when using tabs in this menu.

fixed very minor bugs.

Build BOM: in one part per line, fields are now selectable (like others formats)