preliminary cleanup
Fix some bugs, cleanup, comments.
Newline.
explicit constructors, implemented separately.
Fix the rest of the Grassmann header.
Start cleaning up the body.
Finish body cleanup.
Syntax-error-inducing typos.
Spacing, remove redundant comments
Merge branch 'master' into fix-scalar-multiplication
Consistency with the bikeshedding in #21.
Merge branch 'master' into fix-scalar-multiplication
After pleroy's review.
Merge pull request #23 from eggrobin/fix-scalar-multiplication

Fix scalar multiplication