Make modular exponentiation of polynomial using FLINT interruptable.
Better fix for exponentiation of polys using FLINT nmod and test.
Merge branch 'ticket/17470' into flint_fq_nmod
Simplify FLINT C types use.
Cleanup exponentiation for polynomial over finite fields using FLINT.
Merge branch 'ticket/17470' into flint_fq_nmod
Merge branch 'flint_fq_nmod' into ffisom

Conflicts:
	src/sage/libs/flint/nmod_poly_linkage.pxi
Correctly use FLINT in Javad's code.
Modify FLINT exponentiation test to pass with <= 2Gb of virtual mem.