ps: generalize help text logic, add related translator hints

This commit represents an experiment in nls help text support.

The word --help itself been made translatable along with the
help section names and their abbreviations.  Thus, the work of
the translators will ultimately alter program run-time behavior.

Perhaps someday all "long" options can behave in a similar way
which could offer a considerable benefit to other languages.
Instead of translationg just option descriptions, the long
forms of those options could also be transalated.

This commit also:
 . includes the section abbreviations in --help output
 . isolates all --help support in the ps/help.c module
 . provides (hopefully) meaningful Translator guidance
 . removes --help support from the ps/common.h header
 . removes --help support from the ps/parser.c module
 . eliminates tabs in line with the style of other ps modules
 . eliminates the need for the include/c.h header file

ps/common.h

@@ -12,7 +12,6 @@
 #ifndef PROCPS_PS_H
 #define PROCPS_PS_H
 
-#include "../include/c.h"
 #include "../include/nls.h"
 #include "../proc/procps.h"
 #include "../proc/escape.h"
@@ -27,17 +26,6 @@
 
 /***************** GENERAL DEFINE ********************/
 
-/* usage output sections */
-enum {
-  USAGE_DEFAULT,
-  USAGE_ALL,
-  USAGE_SELECTION,
-  USAGE_LIST,
-  USAGE_OUTPUT,
-  USAGE_THREADS,
-  USAGE_MISC
-};
-
 /* selection list */
 #define SEL_RUID 1
 #define SEL_EUID 2
@@ -325,9 +313,13 @@ extern unsigned        thread_flags;
 extern int             unix_f_option;
 extern int             user_is_number;
 extern int             wchan_is_number;
+extern const char     *the_word_help;
 
 /************************* PS GLOBALS *********************/
 
+/* display.c */
+extern char *myname;
+
 /* sortformat.c */
 extern int defer_sf_option(const char *arg, int source);
 extern const char *process_sf_options(int localbroken);
@@ -338,7 +330,7 @@ extern int want_this_proc(proc_t *buf);
 extern const char *select_bits_setup(void);
 
 /* help.c */
-extern void usage(FILE * out, int section) NORETURN;
+extern void do_help(const char *opt, int rc) NORETURN;
 
 /* global.c */
 extern void self_info(void);