Handle Task-returning methods

Fixes #25
Merge pull request #26 from dahlbyk/gh25

Handle Task-returning methods
GNU Legit
Version bump to 1.1.0
Nuke targets so VS stops messing with our csproj files
Fix syntax highlighting
Added support for request headers. :rocket:

Allows for either hardcoded or dynamic request headers, using a similar
approach to retrofit.
Set content headers and allow header removal/redefinition
Fix 2 of the 3 broken integration tests.

The two GitHub API tests were failing because the API requires a User-Agent header.

NFI what the "PostToRequestBin" test is supposed to do, so I left it broken.
Adds request header info to README
Style stuff I overlooked before
Merge remote-tracking branch 'origin/pr/31'
Version bump to 1.2.0
fixes failing spec
removes unused usings
buildTaskFuncForMethod now takes into consideration the client absolute path
buildVoidTaskFuncForMethod now takes into consideration the client absolute path
fixes the failing specs and adds one more test
reset to java style formating
places catches on the same line as { }