Major bug fix for poly2rect() and update Makefile for --as-needed flag

Fix: Updated Makefile to be compatible with gcc that has linker flag '--as-needed' by default
Fix: Fixed bugs in extend() and poly2rect() of caplet_geo/geoloader.cpp that cause segmentation fault for certain cases.

Special thanks to Hsun-Cheng Lee from Freescale Semiconductor for his thorough testing.