Handle foreignId changes, updateCache on both old and new 

On update of a model, if the foreignId changed (IE, comment moved to different post) the aggregateCache would be updated on the new foreign model, but the cache would remain untouched on the old model, leaving the cache out of sync. These changes look for changes in the foreignId and if detected calls __updateCache on both old and new models, keeping everything in sync.
replace occurrences of PHP 5.4 array shortcut syntax with traditional syntax

this will allow the plug-in to have similar requirements to base CakePHP requirements
check that the associated record exists before saving
Merge pull request #10 from Indemnity83/patch-check-record-exists

check that the associated record exists before saving
Merge pull request #9 from Indemnity83/patch-php-compatibility

plugin requires PHP 5.4, which exceeds CakePHP requirements
Merge pull request #8 from Indemnity83/patch-foreignid-changes

Handle foreignId changes, updateCache on both old and new
Merge pull request #1 from cwbit/master

Sync with original