Third-party checkout extensions compatibility

Onepage checkout extensions may render review section when payment are not 
selected/available. In this case `$payment->getMethodInstance()` will throw an 
exception when `$payment->getMethod()` is empty.
Merge pull request #72 from vovayatsyuk/patch-1

Third-party checkout extensions compatibility
Updated travis config
Working on documentation, need to update th package script to build the extension that magento wants, this includes package.xml etc. for uploading to magento connect
Updated readme with more instructions and updated the package script to build files that can be uploaded to magento connect
Working on refactoring tests
Added a few more tests
Removed shell script
Updated the dependencies to be locked closer to versions
Moved payment method to mirror more of what magento has as its structure, bug fixes, and updated some of the backend templates to display the invoice url so merchants can open up the invoice
Removed unused test file
Cleaned up and removed dead code
Code refactor and cleanup
More code cleanup
renamed bitpay to bitcoin
Changed llc to inc
Bug fixes and updates to make sure the Invoice is being saved
Updated so user cannot fetch transaction info, might be useful later for IPN information
removed unused class
Final updates, checks to make sure IPN is valid by calling bitpay to get invoice and not relying on ipn data
Updated to make sure IPN is valid

Phing was removed

Updated travis build config

Updated travis config to allow failures with php 5.3
Added a script to delete old extension, installing the new extension overrides the previous extension and the previous extensions does not function anymore, merchants should at least disable the previous plugin, the merchant will also need to also remove the extension from core_resource table
Updated to encrypt/decrypt keys to and from the database
Small bug fixes with the package script
Added instructions on how a previous merchant can upgrade to the new 2.x one