Allocate precomputation arrays on the heap
Remove unused secp256k1_fe_inv_all
Check return value of malloc
Merge pull request #138

a5759c5 Check return value of malloc (Pieter Wuille)
2b9388b Remove unused secp256k1_fe_inv_all (Pieter Wuille)
f461b76 Allocate precomputation arrays on the heap (Pieter Wuille)