workaround for buggy strtod is not necessary

Solaris had broken strtod function when parse "Inf" and "Nan". See
solaris.h. This bug has been fixed for all current versions of Solaris (
8, 9, 10). See

http://sunsolve.sun.com/search/document.do?assetkey=1-21-108993-62-1&searchclause=108993-62
http://sunsolve.sun.com/search/document.do?assetkey=1-21-112874-34-1&searchclause=112874-34

Workaround is not necessary now, but I'm not sure if workaround removing
is good idea. There are some possible variants:

1) keep workaround in the code for compatibility with unpatched system
and adjust comment in solaris.h

2) remove workaround and mention required Solaris patch in the
Solaris.FAQ document

3) add some test into configure script and use workaround only on
unpatched system. (It should be nightmare for packagers)

Any suggestion?

Thanks Zdenek