added coding standards from confluence
code block changes
spaces
[contributing] Fix block about pre/post incrment.
[contributing] Move sentence out of code block.
[contributing] table of contents.
[contributing] rename tab section.
changed C to C++
added master contributing.md content
Update to header guard section.

The requirement for how it should be is now presented first. Also OpenSim mostly conforms to the proper header guard naming convention except for classes we plan to deprecate, so removed stale discussion about how wrong OpenSim is.
Fixed typo due to rearrangement of header guard section
Made overriden method more generic

Renamed fictitious base class method that is overriden.
Added override keyword which should be standard moving forward (C++11 and beyond).
Change all instances of the overriden method
[contrib] Clean up table of contents.
[contrib] Update list of contributors.
[contrib] Line length 80 chars.
Resolve merge conflict.
Merge branch 'coding-Standards' of github.com:opensim-org/opensim-core into coding-Standards
[contrib] header gaurd -> guard
[contrib] Fix some formatting related to java.