added ability to manually specify file type on .open
fixes parsing csv with headers option
attempting update to change google_spreadsheet to google_drive
Fix typo in README.markdown
Moved CHARGUESS constant inside Roo::Excel class
Merge pull request #54 from ikido/master

Moved CHARGUESS constant inside Roo::Excel class
Merge pull request #52 from kbroman/master

Fix typo in README.markdown
Merge pull request #37 from vyrak/parse_with_headers_option

fixes parsing csv with headers option
Merge pull request #40 from Kagetsuki/master

Changed Google Spreadsheet to Google Drive
Add spec for Roo::Excel#sheets in hopes of reproing #54
Add regression spec for #37

Apparently #parse is pretty weird in that it includes the header
row in the result, as a hash with header keys and values.
Add changelog entries for #37 and #40
Refactor Roo::Google to avoid querying session#spreadsheet_by_key#worksheets twice in #initialize
Move google_drive to a development dependency so that those not using it aren't forced to install it.
Drop unused Google*Error exceptions.
Convert a basic and essentially pointless test to rspec, as it easily bootstraps our specs.

It also exposes that we need a better way of
testing Roo::Google - the test_roo tests seem to
rely on Hugh Mcgowan's google drive account.
Refactor Roo::GenericSpreadsheet#reload to rely on method calls rather than class detection.

And fix that it was broken since our conversion to hash-based options.
Fix that Libreoffice wasn't declared for autoload.
Rename Openoffice -> OpenOffice, Libreoffice -> LibreOffice, Csv -> CSV,
and redirect the old names to the new constants
Rename Roo::GenericSpreadsheet to Roo::Base.