Update english.php

Added "Submit" text to language file for buttons.
Update contact.tpl

Changed button from "Continue" to "Submit"
Update contact.php

Changed submit button language call.
Update return_form.tpl

Changed return form button from "Continue" to "Submit"
Update return.php

Changed language call for return form submission button from "Continue" to "Submit"
Changed to mysqli check in install/cli_install.php

Close #1680
Fix typo on mysql error message during install.

OC-1735 #close Fixed this today
Added version release number to 2.0.0.0a1 - now set as initial alpha version release.
Fix when unable to refresh the captcha image on some browsers

Close #1668
fix minor typo
Merge pull request #1682 from david-wm/master

Adding return URL to LIPP
Merge pull request #1683 from stan-bg/patch-14

fix minor typo
Removed svn version tracking text in admin footer controller.
Added missing DEFINE to cli_install.php for modifications

Changed function name.

Close #1575
Pagination with rel="next" and re="prev" on Catalog - Resubmit 841f4f4
Added trim to response->clean method. This should prevent any form fields being entered with just white space.
Added validation to sale/customer.php history comment to make sure the admin enters a value.
Products viewed report have less number of product visible.
Merge branch 'master' of git@github.com:opencart/opencart.git
Moved customer history add action to validation method.