Remove leading `*' from all defcustom doc strings.

Remove leading `*' from all defcustom doc strings.
(fortran-tab-mode-default): Remove needless autoload.
(fortran-tab-mode-string): Add help-echo and mouse properties, and
mark as risky.
(fortran-line-length): New buffer-local variable, safe if integer.
(fortran-if-start-re, fortran-end-prog-re1, fortran-end-prog-re):
Change from variables to constants.
(fortran-font-lock-syntactic-keywords): Delete as a variable,
replace with a new function definition.
(fortran-mode): Use fortran-line-length, and
fortran-font-lock-syntactic-keywords as a function.  Add a
hack-local-variables-hook function.
(fortran-line-length, fortran-hack-local-variables): New functions.
(fortran-window-create, fortran-strip-sequence-nos): Doc fix.  Use
fortran-line-length rather than 72.
(fortran-window-create-momentarily): Doc fix.