gcc warnings

[Jeroen Demeyer <jdemeyer@cage.ugent.be>]

Hello list,

this is a list of warnings which gcc 4.4.1 gives when compiling pari.  I 
think the warning about system() is not a big deal, but in my opinion 
the others should (and easily can) be dealt with.

../src/gp/gp.c: In function 'system0':
../src/gp/gp.c:1712: warning: ignoring return value of 'system', 
declared with attribute warn_unused_result
../src/gp/gp_rl.c: In function 'print_escape_string':
../src/gp/gp_rl.c:824: warning: format not a string literal and no 
format arguments
../src/modules/galois.c: In function 'read_obj':
../src/modules/galois.c:328: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result
../src/modules/galois.c: In function 'lirecoset':
../src/modules/galois.c:344: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result
../src/modules/galois.c:345: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result
../src/modules/galois.c:346: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result
../src/modules/galois.c: In function 'lireresolv':
../src/modules/galois.c:357: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result
../src/modules/galois.c:358: warning: ignoring return value of 'fread', 
declared with attribute warn_unused_result