Modified some string comparison and conversion code

Based on results from Assembly Portability analysis.
Created class that allows abstract GeometryContract class to be deserialized.

Thanks to [Tom
DuPont](http://www.tomdupont.net/2014/04/deserialize-abstract-classes-with.html)
:smile_cat:
Updated URLs
Added async versions of methods.
Merge branch 'dotnet-4.5'

Conflicts:
	ElcRestSoeWrapper/ElcWrapper.cs