Minot fixes: Minor coding style issues fix (tab -> spaces). Add missing GetClass to all classes derived from EDA_ITEM. Make debug method Show() only compiled in debug mode.

* Fixed incorrect parameter ordering in gEDA footprint library parser
  which read drill diameter, pad clearance and solder mask clearance.
* Fix FindOpenSSL.cmake version detect bug which was exposed by OpenSSL
  version 1.0.2.

Fix some coverity and cppcheck warnings (most are very minor issues: not initialized members and initialized but not used variables)

Footprint editor: set the default footprint text size to 1 mm. Minor cleaning code. Very minor other fixes.

Fix some minor coverity warnings. Fix a bug in pcad2kicad plugin. Scripting: map BASE_SET. Rename some python bom scripts with better names. Fix erroneous comments and add comments

* Fix default KISYSMOD/KISYS3DMOD (#ifdef typo) for OSX builds.
* Remove setting KIGITHUB from kicad/pcbnew Info.plist in favor of hardcoded default
  setting for OSX builds.
* Remove now unneeded Set3DShapesDefaultPath() and other small things.

Fix some coverity warnings (not initialized members). Add comments. Better (more informative) title in dialog to download .pretty libs.

Fix someminor  coverity warning, and one bug found by coverity in drill report files : buried holes were not properly counted and listed.

lib_dxf: Update to version 0.5.13 (previous: 0.5.11) due to a bug (memory leak) fixed in 0.5.13, which has also more comments, and try to fix most of coverity warnings (not initialized class members).
These members are now initialized, which also fix some other more serious coverity issues.

pcbnew, place file: Fix a minor bug in side identification: a comment in file header was generated with always "top side" id even when the bottom side file was created. Fix also a minor coverity warning (no bug)

Pcbnew, Footprint place file: use standard keywords "top" and "bottom" as board side identifiers instead of external copper layers names, which have no meaning in this fabrication file

Move exact dialog: make all messages translatable. Fix minor issues (some can be Windows specific). Remove useless declarations. Fix coding style issues
Fix minor warnings from cppcheck.

Fix also very minor warnings detected by cppcheck.

Pcbnew: fix bug  #142348 (airwire does not always appear after deleting a track). Very minor other fixes.