Fixing potential attack vector and instability in External Submodule

Fixes #407
Syntax
Backwards compatibility method
adjusting generator for last_login_from_ip_address attribute
Changed sqlite3 gem.
Merge pull request #437 from vote539/external

Fixing potential attack vector and instability in External Submodule
Merge pull request #438 from GBH/activity_logging_generator

adjusting generator for last_login_from_ip_address attribute
Merge pull request #441 from sandrew/master

Unlock token in bruteforce protection is set to the model after the mail is sent
Merge pull request #442 from totallymike/sqlite_gem_update

Changed sqlite3 gem.
Regenerate gemspec for version 0.8.1
Version bump to 0.8.2
Regenerate gemspec for version 0.8.2
Use change method in migrations
add support for state parameter for oauth 2
add remember me property to external login
Merge pull request #458 from efrat-safanov/master

add support for state parameter for oauth 2
Proper memoization of #current_user

When no one was logged in, it used to return `false` at the first time,
then `nil` in all subsequent calls.  Now always returns `false`.
Merge pull request #461 from appdate/current-user-memoization

Proper memoization of #current_user
Merge pull request #447 from Hispano/master

Use change method in migrations instead of self.up and self.down
Small readme changes