Removes static variable that causes linking errors.
Camera parameters are now eigen vectors.
Adds non-const getter for params eigen vector.
Fixes ceres templating issure.
Formatting updates.
Adds undef to unpolluted namespace (Thanks to @chachi for the comment)
Fixes linker errors in constexpr by removing static.
Merge pull request #15 from arpg/fix/revert-params-to-eigen

Fix/revert params to eigen