Added automatic material naming.

Materials will be renamed based on their CryExportNode.
Added automatic UV apply to meshes without.

New method to apply UV maps automatically, useful for files with a lot
of meshes. Added new icon und description to Material renaming and names
have better compatibility with RC now.
Improved speed and code readability.

Fixed line breaks causing invalid characters in Blender UI.
Heeding PEP8 guidelines.
Improved variable names.
Improved material renaming loop.
Reworked renaming.

All materials are always updated to save the strict number sequence per
CryExportNode that is required for RC.
Fixed wrong material assignment in CryEngine when Blender scene contains
materials of Objects that were previously in CryExportNodes but not
anymore.
Fixed comments and added minor speedup.

Removed obsolete methods.
Changed comments according to PEP 257 Docstring Conventions.
Fixed wrong function names.
Added existing groups to AddCryExportNode.

AddCryExportNode has a new feature: Add selected objects to an existing
CryExportNode. This had to be done in this branch since this method was
already modified by that branch.
Added properties removal, fixed renaming.

Added RemoveCryBlendProperties.
Fixed bad renaming when "___" (or longer) is in a material name.
Moved utility functions to utils.
Removed CryBlendMaterial call for minor speedup.
Fixed wrong function call.
Fixed blank lines.

Added/Removed blank lines to meet PEP-8 standards.
Splitted revertMaterialNames() for easier readability.
Removed unnecessary return.
Resolved conflicts with other branches.
Merge branch 'roidanton-feature/material-naming' into develop