Stealth dependency in textproc/redland

[Mel Flynn]

Hi,

the naughty rasqal/configure will try to find libgmp and link with it if 
found. This must have been installed during a previous package build and after 
cleaning environment and rebuilding x11/kdebase4-runtime with 
USE_PACKAGE_DEPENDS I got this error:
(Soprano::PluginManager) found no soprano plugin at  
"/usr/local/lib/soprano/libsoprano_redlandbackend.so"
Failed to create memory model
*** Error code 1
1 error
*** Error code 2

I traced this to the now absent libgmp.so.8. I'm a little short on time, but 
if needed can patch and PR it. Would you like this through OPTIONS asking for 
libgmp or disable it all together?
-- 
Mel