* http.c (test_parse_range_header): New function to test the
function for parsing the HTTP/1.1 Content-Range header.
* test.[ch]: Same
* http.c (parse_content_range): Fix parsing code. Fail on scenarios
mentioned in rfc 7233.
* Makefile.am: Added new source files hsts.c and hsts.h.
* http.c (parse_strict_transport_security): new function for STS header
parsing.
(gethttp): update the HSTS store.
* http.h: new include "hsts.h".
* init.c: new options --hsts and --hsts-file.
* main.c (get_hsts_database, load_hsts, save_hsts): new functions.
New options --no-hsts and --hsts-file added to help.
(main): load and save HSTS store.
* options.h: new variables for supporting --hsts and --hsts-file.
* retr.c (retrieve_url): rewrite the URI according to the HSTS policy before
entering http_loop.
* test.c, test.h: new unit tests for HSTS.
* utils.c, utils.h (countchars): new function.
* wget.h: new preprocessor check.
* hsts.c, hsts.h: new files with the HSTS engine implementation.
Added support for HTTP Strict Transport Security (HSTS), as defined by RFC
6797.
In test.c, this patch changes the type of program_argstring to char *
from a const char *. This is because, we use a char * string in the rest
of the program and declare an extern accordingly. Removing the const
type helps in keeping the code cleaner at no extra cost.
