[Update] PhpDoc
replace occurances of `__()` with `I18n::translate`
Replaced occurances of `__()` with `I18n::translate` in Exception and
Validation, as well as the view files error.php and stats.php

https://github.com/kohana/core/commit/4603282fa9eec4ffd9edcd976c5c2875331fa6e1
Set and reset mb_substitute_character for mb_convert_encoding

https://github.com/kohana/core/commit/d2b6572408f1ee405b19fec5b92bf825a40eebfa
Update user_agents.php

https://github.com/kohana/core/commit/c5f36c7e01748ffe295d2f6ffff3fc151297db6b
keys are used to match for occurances in User-Agent
also removed redundant Googlebot-Mobile: googlebot will match that

https://github.com/kohana/core/commit/8c76bbc681140679e0167947a2677b62e35e5adf
Update Encrypt.php
* Not too long ago, @defuse informed me that `MCRYPT_DEV_URANDOM` on Windows works as well as it does on BSD/Linux.
* Don't allow insecure, predictable random numbers for IVs

https://github.com/kohana/core/commit/cecb8c20394c015dfd6876df185d8faf39df528b
Update Encrypt.php

https://github.com/kohana/core/commit/fd633a52bf07f04711d9b3e5292db430e309e90b
Remove more direct access checks

https://github.com/kohana/core/commit/cd1ec98b4a167fbe8ce1b8e1249566ccfc6bf7bc
[ReFactoring] fix with namespace
Typo
Remove more direct access checks
Add exit to the top of log files

https://github.com/kohana/core/commit/3f26f6e854179bc10745bd8b2c9bc745a89fe2c0
Use __DIR__ to mock module directory in test

https://github.com/kohana/core/commit/dd926956ba888bbb9b596490d563de59a3c6ad5c