#9 Improve const correctness

[Markus Elfring]

Would you like to apply the advices from the article
"http://en.wikipedia.org/wiki/Const_correctness" to
your sources?
I suggest to add the key word "const" to the type
specifiers for parameters like the following examples.

http://cvs.sourceforge.net/viewcvs.py/radeontweaker/radeontweaker/src/RT.H?rev=1.28&view=markup
profile_name_old (function "rt_load_profile")
profile_name, profile_author, profile_comments
(function "rt_save_profile")
reg_value (function "rt_.et_option.*")