Changed cmake config to use RPATH as default.
Added map of shared library extensions - consulting platform.system() to determine the correct etension.
Changed clib.load() calls to use library names without extension.
Changed rms and well packages to use __init__ based package init + loading library without extension.
Using lower() on platform key. Added platform key aliases.
Merge pull request #413 from joakim-hove/shared-lib-loading

Shared lib loading