New algorithms for merging projections

Improved algorithm for merging projection rectangles. Now the projection distance is considered when merging projections. An additional function removeBadProjection() is performed after the merge to improve the condition number of system matrices and therefore the numerical behaviors of the solution. The original version of mergeProjection can be reactivated by uncommenting a flag in caplet_geo/debug.h.

Improved integral robustness

Some integrals used to erroneously generate NaN or Inf values when the boundary coordinates of two basis functions are too close to each other. In this release, we there lower the "zero" for double precision floating points from 1e-10 to 1e-12 and add additional checks for analytical integrals.

The more stringent zero definition (=1e-12) brings a better capacitance accuracy compared to reference values (have observed more than 1% accuracy improvement). The additional checks have a very slight impact on extraction performance so we decide to set this feature on by default. The flag is ROBUST_INTEGRAL_CHECK in caplet_solver/include/caplet_parameter.h.

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.

Improved compatibility

Now with the enforcement of integer output from caplet_gds2geo, caplet_geo can safely make the assumption that the input .geo files contain only integer values. This can resolve inconsistent formats generated from various layout tools.

First release on Github with several fixes and new documents

New: Hosted a repo on GitHub.
New: Prepared this README.md file.
New: Tested installation with various Qt versions.
Fix: Improved installation experience.
Fix: Cleaned up several compilation warnings.