improve stlport4 check in libtool.m4

[Marc Glisse]

Hello,

libtool.m4 contains a test that may set solaris_use_stlport4 and disable 
the addition of "-library=Cstd,Crun" (which is a useful addition when 
creating shared objects with the default standard library).

I would just like to replace the test:

*" -library=stlport4 "*)

by:

*" -library=stlport4 "* | *" -library=no%Cstd "*)

(note that this code occurs in 2 places in the file, both of which could 
be changed)

The point is that it is possible to use yet an other standard library than 
stlport4 (indeed the kde on solaris effort is using the apache stdcxx), in 
which case we also want to avoid "-library=Cstd". The compiler flag that 
disables Cstd is -library=no%Cstd (-library=stlport4 is actually an alias 
for -library=no%Cstd,stlport4).

Note that the variable could be renamed since it is also used on linux, 
not only solaris, and with this patch would also be used with other 
alternate C++ standard libraries, but that does not really matter.

--
Marc Glisse