Fail if init_module_paths called more than once

MSP-11672

Calling init_module_paths takes 6 seconds on my machine even when there are no
files to that are changed just because it takes that long to walk the
directories and gather the mtime for each file.  Therefore, calling it
more than once should be avoided.  Also, there is no reason to call it
twice as to add paths later, `modules.add_module_paths` should be used.
init_module_paths once in msfconsole

MSP-11672

Pass `'DeferModuleLoads' => false` to `Msf::Simple::Framework.create` so
that `framework.modules.init_module_paths` is only called once (directly
in `Msf::Ui::Console::Driver#initialize`) instead of twice (in
`Msf::Simple::Framework.create` and `Msf::Ui::Console::Driver#initialize).
Merge branch 'master' into bug/MSP-11672/double-init-module-paths

MSP-11672
Travis shouldnt test gh-pages and friends

This adds a blacklist of branches that Travis shouldn't run tests
against.
Also .gitignore the source directory for metakitty
Slight fixes to grammar/desc/whitespace

Note that the format_all_drives module had a pile of CRLFs that should
have been caught by msftidy. Not sure why it didn't.
Fix #4307 - Check action for nil

Auxiiary modules already do this, but looks like we forgot to do the
same for post modules.

I also changed the error to allow "reason" in order to be more
informative about what the user should do.

Fix #4307
Remove junk code
Land #4294, msfconsole speedups on module load

Related to #4257 and #4195 vaguely, and possibly even #4147.
Land #4303, Travis build blacklist

gh-pages, metakitty
Land #4314, @todb-r7's module cleanup
Land #4319, @wchen-r7's fix for #4307