Fix whitespace related license issues.

Fix whitespace related license issues.

Several copies of the licenses in files contained whitespace related
problems.  Two cases are addressed here, the first is two spaces
after a period which appears between "PURPOSE." and "See". The other
is a space after the last forward slash in the URL. Both issues are
corrected and the licenses now match the official textual description
of the license (and the other license in the sources).

Since these whitespaces changes do not alter the paragraph structure of
the license, nor create new sentences, they do not change the license.