Fix some gross mistakes.
* lisp/muse-blosxom.el (muse-blosxom-update-page-date-alist): Fix several
gross misspellings.
* lisp/muse-project.el (muse-project-file-entries): If
`muse-file-extension' is defined, use it to filter the entries.
* lisp/muse.el (muse-file-extension): Fix messed up attempt to set
variable. Move higher in file.
* lisp/muse.el (muse-update-ignored-extensions-regexp): Use given
argument instead of the real name of the variable.
git-archimport-id: mwolson@gnu.org--2005/muse--main--1.0--patch-112