Initial resubmission.
"Приведение в чувство".
Cleanup/beautify.
Compare/Equals redesign.
SemVer.
Renamed.
Retargeted outputs.
Fixed SatelliteContractVersion.
First round of documenting and contracting. Contains breaking changes!
Code Contracts for collections and interfaces + code analysis.
XKey allowed to be null.
XObject.Clone() added back.
.NET Framework 4.5 support added.
WinRT support added. Resource strings replaced with string constants.
Resource strings are turned into resources once again.
DCLCORE-2
Proper code contracts.

Working DCLCORE-2 : Добавить контракты и проверку контрактов в XCollection и наследников
XKey bug fixed.
Merge branch 'master' of mskhqgit1:digillect/common-libs/core
DCLCORE-2
Code contracts for SL4/WP7 targets.

Working DCLCORE-2 : Добавить контракты и проверку контрактов в XCollection и наследников
DCLCORE-2
Code contracts for release builds.

Working DCLCORE-2 : Добавить контракты и проверку контрактов в XCollection и наследников