Added support / Sink for Microsoft Application Insights
Merge pull request #149 from jbattermann/master

Added Sink for Microsoft Application Insights for Visual Studio Online
Support :u and :w as format specifiers for UPPERCASE and lowercase output respectively; only effective in output templates. Fixes #88 and #151.
Merge branch 'master' of https://github.com/serilog/serilog

Conflicts:
	Serilog.sln
Test .csproj cleanup (fixes #139).
Fixes #152 - convert null/empty strings appropriately when setting Nullable<T> values from <appSettings>.