Add request body specs
Add content-length and switch from 504 to 408

- Add Content-Length to requests
- Use 408 status code for timeout
- Refactor HttpSetup
Refactor Content-Length
Merge pull request #14 from timhall/content-length

Content length
v2.0.2
Merge branch 'master' into proxy-functionality

Conflicts:
	specs/Excel-REST - Specs.xlsm
	src/RestClient.cls
	src/RestClientBase.bas
Add RestClient.SetProxy method