Info and Errors and other bug fixes

Special thanks to @tswagger for this commit

Added flashdata boolean to error() and info() allowing the option for errors/messages to only remain for current page.

Added clear_errors() and clear_infos() which removes all errors and infos from Aauth storage as well as flashdata storage

Loaded flashdata into errors and infos on construct in order to fully utilize flashdata (as a result, keep_errors() and keep_infos() now work properly)

Added boolean return value to login_fast()

Remove redundant indexes from Aauth_v2.sql

Removed bool return value from get_errors_array() and get_infos_array(). As "array" is in the method name, should only return array. Change should remain backwards compatible as empty array will still evaluate to "false".

Fix bug in which "is_allowed" returns true if user is logged in and has access to perm_id=1 and perm is non-existant.

Modified list_user_var_keys() to return an array so that it can be looped through

Fixed duplicate message when sending password reset email, line 424

Modified lang-file constants to include prefix. This will help avoid collisions. Also added a few missing items to the lang-file

Updated SQL file to be a bit more efficient.

Modified keep_infos() and keep_errors() to include non-flash data values on optional boolean parameter.