Fix some default properties: OutputType has default to Exe. AssemblyName defaults to the project file name, not RootNamespace.
Target items related fixes - give diagnostic outputs for initial items. Evaluate item condition.
Some parser error message got source string for Condition evaluation.
ProjectCollection.DefaultToolsVersion is settable.
Add missing exception types.
update .csproj.
Remove private sln/csproj files.
Merge branch 'armhf' of github.com:alexrp/mono
[sgen] Fix build on Linux.
Sanitize the kqueue check in configure.in.
Fix android-specific build (use of unassigned variable).
[corlib] Replace manual array resize with Resize call
[mcs] Report all failure errors in lambda conversions. Fixes #16513
[mcs] Report nice error instead of crash for cyclic type forwarders. Fixes #16385
[sgen] Never invoke libc’s memmove() or bzero().

Those two functions are not guaranteed to do word-atomic copying or
zeroing under any circumstances.  memmove() on OSX, for instance,
has an SSE optimized variant that, if source and destination are 8-byte,
but not 16-byte aligned, will copy the first 8 bytes byte-wise, which can
crash SGen.

Fixes https://bugzilla.xamarin.com/show_bug.cgi?id=16449.
[sdb] Support a setpgid=y/n option to --debugger-agent.
Fix the build.
[xbuild]: Allow expressions inside a dynamic <ItemGroup>'s metadata.

Fixes #14661.
[xbuild]: Provide diagnostic logging of all executed targets.
[xbuild]: Check a <Target>'s "Returns" first, then fall-back to "Outputs".

This fixes a problem with the "Microsoft.Bcl.Build" NuGet package, which
overrides the "GetTargetPath" target in a custom .targets file and uses
"Returns" instead of "Outputs".