converted README to restructured text. closes #24
made installation instructions more modular for different operating systems
ShellError now detects when an executable is not installed and gives a helpful error message pointing to the documentation
added sensible fallback to pdfminer (a python package) for pdf_parser
added note about installing python header files for osx
moved the installation instructions into standalone url to make it easier to find them
Merge pull request #21 from deanmalmgren/more-robust-operating-system

pdftotext isn't included on non-linux OSes
Merge pull request #29 from christomitov/master

.odt support
updated changelog with recent PRs and updated documentation for odt_parser
forgot to update supporting list with .odt
added a related projects section to the documentation
forgot to rename the README.rst file in setup.py
tesseract for gif,png,jpg support