Use Squared Distance instead of Distance in Simplify

[pramsey]

By avoiding sqrt() and using getPoint_cp, speed up the simplification routines, particularly on large polygons. Patch from J. Santana.

[pramsey]

Committed in 2.1 at r13247, trunk at r13248

[strk]

A couple of warnings left:

measures.c:2159:1: warning: no previous prototype for 'distance2d_sqr_pt_pt' [-Wmissing-prototypes]
 distance2d_sqr_pt_pt(const POINT2D *p1, const POINT2D *p2)
 ^
measures.c:2223:1: warning: no previous prototype for 'distance2d_sqr_pt_seg' [-Wmissing-prototypes]
 distance2d_sqr_pt_seg(const POINT2D *p, const POINT2D *A, const POINT2D *B)
 ^

[strk]

btw, the algo was using square distance in its beginning (11 years ago). I dont' remember when it got changed to use flat distance. REF: r329

[strk]

I was wrong, as of r329 only variable _names_ had the "sqared" label, but the implementation was bogus. The fix, later, went the way to use flat distance rather than squared one.

Anyway, simplify tests are failing for me, both in unit test and regress. Am I the only one ?

[strk]

I was the only one, reconfiguring the sourcetree gave me a green