Correct instructions for Vagrant issues.

If you don't have `iniparse`, then `vagrant up` and `vagrant package install iniparse` do not work. You need to install it as a plugin.
Corrected links in documentation
Merge pull request #31 from PrajitR/vagrant_instructions

Correct instructions for Vagrant issues.
adding iniparse installation instructions to docs
Merge pull request #32 from smilli/master

Corrected links in documentation
Fixing doc reference, draft of CONTRIBUTING.md
moved the substantitive parts of the CONTRIBUTING guide into the documentation
Merge branch 'master' of github.com:deanmalmgren/textract
Merge branch 'master' of https://github.com/christomitov/textract
code/comment changes