Added CategoryErrorLevelActivationStrategy, which enables setting the
Error Level threshold per log channel.
Refactored / Renamed the CategoryErrorLevelActivationStrategy to the
more appropriate ChannelLevelActivationStrategy.
Fixed phpdoc, typo and indentation issues.
s/NativeMailHandler/NativeMailerHandler
Merge pull request #208 from raphaelstolt/patch-1

s/NativeMailHandler/NativeMailerHandler
added ctags generated 'tags' files to .gitingore for
added support for Pushover API priority brought up by SteveEdson in issue #187; the priority levels can be adjusted either through the handler's constructor or setters
Update .gitignore

removing tags from .gitignore following stof suggestion
Update PushoverHandler.php

simplifying the priority level setting if condition following stof suggestion
Merge remote-tracking branch 'ArturMoczulski/PushoverPriority'
CS fixes, refs #209
add error_log handler

[error_log](http://www.php.net/manual/en/function.error-log.php) handler
to send output to webserver SAPI handler (directly or indirectly)
Merge remote-tracking branch 'glensc/errorlog'
Add new handler to the README
Merge remote-tracking branch 'netmikey/master'
Fix a few details and add docs to the ChannelLevelActivationStrategy, refs #186
Added an handler for NewRelic:
* implemented a test which verifies that the fallback handler handles records when the NewRelic PHP extension is not installes
* implemented the actual handler
updated the documentation
removed the logic for the fallback handler, its out of place, adapted the "test"