Squashed 'sglib/' changes from 0ec7b66..6f2db34

6f2db34 Added and updated almost all Contents.m files
5fe89bd added pushdirect option to sglib-subtree
1701380 Update unittest for compute_pce_matrix (better coverage)
d011745 Huge cleanup and moving into packages sfem and pce.
df15bfb Changed funcall unittest to be independent of current format options.

git-subtree-dir: sglib
git-subtree-split: 6f2db34ad0fe2abb3fec208b198449467ff2d72a
Merge commit '1d5c43c3f4faffc935e62fe6ed8bb330314aad11'