[LyX/master] Add default TransformID enum value

[Yuriy Skalko]

>> I have removed the unneeded autoconf parts and remove the machinery to build
>> a boost library (only regex needed it). The gain is only 2M out of 23.
> 

Seems like we can also get rid of boost/fusion without any consequences 
and get another ~4M.

> 
> I am somewhat confused here. If we don't need to build boost anymore,
> why we include it at all?
> 
> Pavel

It is mostly header-only library with some exceptions (as excluded regex).


Yuriy