HOTFIX: Reset the initial paramaters on LK

When performing a single fitting of LK, we weren't resetting the
parameters. Luckily, this is a simple fix.
HOTFIX: Landmark setting with pointclouds is broken!

Accidentally broke the setter for PointClouds! This is now
fixed and a test is added to check for it
Merge pull request #350 from patricksnape/master

HOTFIX: Landmark setting with pointclouds is broken!
Merge branch 'master' into lk_hotfix
Extends the hotfix to CLMs and parametric-based SDMs
Merge pull request #348 from patricksnape/lk_hotfix

HOTFIX: Reset the initial paramaters on LK
Remove Levenberg-Marquardt

It currently doesn't work properly, so we should remove it until
it does. This also fixes the docs.
Merge pull request #353 from patricksnape/lm_fix

Remove Levenberg-Marquardt