First pass at ContentSize implementation.
Added ContentSize tests.
Merge branch 'master' into ContentSize
Use Content-Length to grow bytes buffer in ContentSize branch.
Adjust type of size in fillReadBuffer for ContentSize
Merge branch 'master' into ContentSize

Conflicts:
	fetcher.go
	test/fetcher_test.go
Use lower case n rather than uppercase N for variable name in
ContentSize.
Merge branch 'master' into ContentSize
Merge pull request #88 from iParadigms/ContentSize

Content size