fixed cp34951

decoding of not completely read utf-8 does not raise exception
decoding of invalid utf-8 raises decoding (was encoding) exception
added dedicated test
moved workaround into separate classes
updated documentation link
fixed cp35048 - renamed second argument from radix to base
fixed cp39094

throw SyntaxError when comment is passed to compile in "single" mode
Fix CP#35049 - .NET 4.5 not included in installer.

How I missed that I'll never know.
Update version to 2.7.5 beta 1.
Merge remote-tracking branch 'paweljasinski/cp30940' into ipy-2.7-maint
Merge remote-tracking branch 'paweljasinski/cp34951' into ipy-2.7-maint