Log Message:
Updated isl to 0.17.1.

Provided by Kai-Uwe Eckhardt in private mail.

version: 0.17.1
date: Fri May  6 12:02:48 CEST 2016
changes:
	- fix bug in coalescing treatment
---
version: 0.17
date: Tue May  3 14:26:43 CEST 2016
changes:
	- optionally combine SCCs incrementally in scheduler
	- optionally maximize coincidence in scheduler
	- optionally avoid loop coalescing in scheduler
	- fix handling of nested integer divisions
	- optionally detect min/max expressions during AST generation
	- minor AST generator improvements
	- simplify stride constraints
	- improve support for expansions in schedule trees
---
version: 0.16.1
date: Thu Jan 14 18:08:06 CET 2016
changes:
	- fix bug in simplification
---
version: 0.16
date: Tue Jan 12 09:56:16 CET 2016
changes:
	- add 32 bit integer optimization for IMath
	- minor AST generator improvements
	- add isl_union_flow_get_full_{may,must}_dependence
	- minor improvements to Python bindings
	- minor improvements to set and map printing
---
version: 0.15
date: Thu Jun 11 12:45:33 CEST 2015
changes:
	- improve coalescing
	- add isl_union_access_info_compute_flow
	- add mark nodes in AST
	- add isl_union_pw_aff and isl_multi_union_pw_aff
	- add schedule trees
	- deprecate band forests
	- deprecate separation_class AST generation option
	- introduce isl_bool and isl_stat types