Update doc xls ppt adp icons

Currently in Lucid the icons for Word Powerpoint Excel and Access have W, P, X and A EXACTLY like that of OS X. It's understandable that there should be some similarity for converts. However, the similarity is only there for Mac converts. The similarity for Word for example should be "Blue W" as that is present in the versions of Word for Windows as well. The new Ubuntu font should be used for the icons. It helps with Ubuntu's identity and will be a step away from the OS X cloning it is being accused of as of late