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Wrap more AST types, test

See merge request inducer/islpy!22

Add test for context pickling

See merge request inducer/islpy!21

Support isl_bool pointer arguments

corrects the usage of isl_aff_move_dims

See merge request inducer/islpy!20

Let methods taking Val accept more integer types (including numpy int) (Closes #4)

Closes #4

See merge request !19

Install pcpp in barvinok build

See merge request !18

 Update for isl 0.22pre, add isl header preprocessing to gen_wrap