Tweaking style related functions
Switched the ocurrencies of the genre '(lambda ()) or (lambda ())
to the `function' shorthand notation, also replaced the last
with its shorthand notation.

Created a non-interactive function named `cperl-goto-line' that
goes to a specific line within a buffer, the purpose of this was
to replace the ocurrencies of goto-line which is an interactive
function.
Improved the function `cperl-goto-line' to have the same behaviour than
the intercative function `goto-line', now when passed a buffer it goes
to that buffer line instead of current one.
Finished applying the `function' shorthand notation in all
anonymous functions.
Improved the function `cperl-add-style' so that it can validate new styles
Created the a function `cperl-add-style' that adds a new user
defined style, that can be used later by calling `cperl-set-style'.

Used the `function' shorthand notation in all ocurrencies of anynimous
functions.

Created a function `cperl-goto-line' that behaves in the same maner as
the interactive function `goto-line', since when compiling cperl-mode
warnings are issued when using interactive functions in Lisp code.