* remove support for log-double
* move functions to utils
* move functions to utils
* cleanup
* print command line
* add functions logspace and linspace
* changed command line arguments
* cleaned up code
* add function swap
* remove obsolete prototype
* remove command line option -X
* minor changes
* add getter and setter functions
* make getter and setter functions consistent
* fix a bug in casimir_set_lmax
* set a reasonable value for lmax in casimir_init
* remove asserts
* change name of constants
* the braces are redundant