Update protected/extensions/yiicomp/components/ImageHandler/CImageHandler.php

Enable alpha for text() method.
Allows to make text with various amount of transparency.
(0 - opaque, 127 - transparent)
Update protected/extensions/yiicomp/components/ImageHandler/CImageHandler.php

Additional positions for watermark() and text() methods
Merge pull request #1 from Koduc/master

CImageHandler: added text alpha option and additional text positions (by Koduc)
CImageHandler: documentation update