Update MP1 to NET4. PART 1.
Merge branch 'master' into MP1-4069-Migrate_to_NET4

Conflicts:
	TvEngine3/TVLibrary/TvThumbnails/TvThumbnails.csproj
MP1-4069 : Fix detection of Fonts dir.
MP1-4069 : Add Warning when NET4.0 is not installed.
Add code (not enable) to check NET4.5 install (for later).
MP1-4069 : NET4.0 only checking (no need to check for SP1)
Merge remote-tracking branch 'remotes/upstream/MP1-4069-Migrate_to_NET4' into 1.5.0Fork

Conflicts:
	Tools/InstallationScripts/include-MP-PreBuild.nsh
	TvEngine3/TVLibrary/Plugins/WebEPG/WebEPG/WebEPG.csproj
	mediaportal/Core/Core.csproj
	mediaportal/Databases/Databases.csproj
	mediaportal/ProcessPlugins/ProcessPlugins.csproj
	mediaportal/WindowPlugins/WindowPlugins.csproj