essential matrix estimation from 5 pt alg in vxl
split camera intrinsics conversion functions out for reuse
updated interface to accept either 1 or 2 calibration matrices
make API similar to estimate_homography
added inlier computation
register vxl estimate essential matrix
added cross product matrix function
swapped role of left and right points
corrected equation + should be *
need to take absolute value of distance
added tests for essential matrix estimation
added test with noisy points
use more than 8 test points
add config parameters to essential matrix estimation
Declare type_name() and impl_name() methods virtual.

It is more apparent that a method is virtual if it is always
declared as virtual.
Make destructor virtual.
Update release notes
Add virtual keyword to impl_name() method.
Added missing semicolon that was preventing successful build
Merge branch 'Purg-ghp/dev/fix-semicolon-typo' into release

* Purg-ghp/dev/fix-semicolon-typo:
  Added missing semicolon that was preventing successful build