Eeschema find bug fixes. (fixes lp:1199689)

* Force search when wrap past end of list option changes state.
* Fix SCH_FIELD::Matches() for bug in user defined fields which have an ID
  of -1.
* Minor improvements to the find data names to improve source code readability.
Initial release of pl_editor, the page layout and title block editor.
Eeschema: fix subtle find bug when at the end of the search list.  (fixes lp 1199689)
Add margin values control in pl_editor, and remove margin definition from class PAGE_INFO.
pl_editor: add config options
Fix GOST compatibility.
Initial release of pl_editor, the page layout and title block editor.
Bug #1202761 (Off centre zoom )
Pl_Editor: Fix wx28 compatibility
Fix an issue in Debug mode
Pl_Editor: bug fixes (default values not saved, and duplicate item names, when adding items)
Pl_Editor: add some hot keys. Fix some rounding issues.
Pl_Editor: fix a very minor issue when displaying the page size in status bar.
Add GOST page layout description files in template
Very minor code cleaning
Pl_Editor: title block texts can be multiline (use" \n" :  a '\' followed by a 'n' to create a new line inside a text)
Very minor code cleaning.
Pl_Editor: add undo/redo commands.
Commit missing file
Fix minor debug build error.
Fix pad bounding box calculation bug. (fixes lp:1202828)