minor refactoring
added Nunit exe and psake task to for running unit and integration tests,
added ILMerge.exe and psake task for merging all of CmsLite's dependencies (CmsLite.Data, Core, Utils, Domains, etc...) into a single .dll
update psake nuget task to use the merged dll for CmsLite,
fixed tests so they can be run all at once now, both unit and integration - all successful