writerfilter: switch to the oox FastTokenHandler

Possibly they did something different in the past, but currently they do
the same. This commit just switches the handler, the newly unused code
will be removed in a later commit.

Change-Id: Ic5bade876c264e025543728916d9bcd871e32b9b
unused writerfilter::ooxml::OOXMLFastTokenHandler

This makes libwriterfilterlo.so smaller by 500KB in a stripped dbgutil
build.

Change-Id: I0046251a0fe83ceee6f585f17707e4ecf53996b6
unused tokens-to-xml.sed

Change-Id: I274cdeddde53472e1d4d2188f88269a70677a1fd
pep8 fixes

Change-Id: Iba89cca1dd06e133d7a23f1695b262209e13cec2
fix C++11ism

Change-Id: I93f8bbdc9b0b326fa6334640e1d65b862dba6f22