Compatibility for KSP 0.23

Very minor changes.  Have a look at the commented out sections in KLFManager.cs:

* fixed editor lock checks. (see commented out sections)
* fixed reference to new Propellant class.

Other changes:

* updated version to 0.7.3 (compatible with server 0.7.1+)
* using single AssemblyInfo across 3 projects (see monomake)
* fixed line-endings
* fixed .gitignore to discard non-code and .gitattributes to enforce default/sane line endings
* commented out some unused variables to remove compile warnings