Update in `struct_enum.out` format

Slight change to the output format for struct_enum.out. This will have no effect on any structure with fewer that 40 atoms in the primitive cell. Cases with more than 40 atoms broke the makeStr.py script because the output of equivalent atoms wrapped on to a second line.

Small enhancement

Made two small changes, one in symlib and one in enumlib. The tolerance for error checking in a 3x3 matrix inverse was relaxed (increased by 10x, to 10d-13). This avoids the error triggering for large supercells when it shouldn't merely due to roundoff errors. This update was spurred by issue #117. That input now works just fine on a fresh checkout and recompile of both libraries.

Added automatic version reporting.

Merge pull request #91 from glwhart/master

Added automatic versioning functionality

First tagged release

Tagging this release so that enumlib can be added to the homebrew package manager.