Fixed memory leak in fits::wcs assignment operator.
Fixed crashes and bugs in fits::setkey(). Added comments to code.
Added fits::make_wcs_header() [WIP].
Improved checks for in_convex_hull().
Fixed convex_hull_distance.
Added pick_elements().
Added checks to element().
Added first() and last().
Fixed (again and finally!) convex_hull_distance
Fixed writing END keyword when manually setting header in FITS images.
Merge branch 'nocpp14' of github.com:cschreib/phypp into nocpp14
Removed buggy code not belonging to this branch.