Prepare for a reverse_http stager
Pymet reverse_http stager basic implementation
Patch pymeterp http settings
Escape inserted vars and fix core_loadlib
Pymeterp http proxy and user agent support
Fix pymeterp bugs from testing in osx and python3
Shorten the reverse_http stager by renaming a var
Add the test context to payloads_spec for py http
Fix two typos for payload specs
Restructure parts of Author, fix some doc bugs.
Fix nonsensical spec.
Comment out boot cucumber tests

This is in response to the slowness noticed over the last few days and
unrelated changes causing travis failures. For example:

https://github.com/rapid7/metasploit-framework/pull/4252#issuecomment-64923343
Fix os detection

See #4283
Fix os detection

See #3373
Land #4270, Msf::Author cleanup and improvements
Land #4292, remove os_flavor usage.
Cosmetic tweaks for #4225
Python reverse_http stager, lands #4225
Merge master with merge of PR #4225
Land #4289, Travis/Cucumber boot test fix