Added AdobeBlank

This way when fonts don't have a glyph, the preview will be blank instead of showing the glyph from a default font such as Helvetica, Arial or a Devangari equivalent. Useful especially in the case of fonts without Latin.
Merge pull request #6 from weiweihuanghuang/master

Added AdobeBlank
renamed test font directory
added Chandas (+2,7MB)
merging two arrays
added test folder