top: utilize getopt and introduce long cmdline options

For quite some time now, top has stood out like a sore
thumb regarding the approach to cmdline options & help
text.  Only short options were used and that same help
text was displayed for '-h' (help) plus 'v' (version).

[ also, top 'rolled his own' when it came to parsing ]
[ options while avoiding that getopt implementation. ]

Well, with this commit all of that has changed and top
now has added a long form of his options. Additionally
he employs getopt_long() for the bulk of that parsing.

[ however, top will still avoid separate fputs calls ]
[ characteristic of other procps-ng programs when it ]
[ comes to help. rather all such text is one string. ]

Along the way, the following major getopt deficiencies
were addressed, assuming the absence of a new #define:

* an equals sign ('=') is allowed on both option forms

* whitespace is allowed before & after the equals sign

* optional arguments needn't abut their related option
for short form nor is an '=' required with either form

Signed-off-by: Jim Warner <james.warner@comcast.net>

top/top_nls.h

@@ -78,7 +78,7 @@ enum norm_nls {
    OSEL_casenot_txt, OSEL_caseyes_txt, OSEL_errdelm_fmt, OSEL_errdups_txt,
    OSEL_errvalu_fmt, OSEL_prompts_fmt, OSEL_statlin_fmt, RC_bad_entry_fmt,
    RC_bad_files_fmt, SCROLL_coord_fmt, SELECT_clash_txt, THREADS_show_fmt,
-   TIME_accumed_fmt, UNKNOWN_cmds_txt, UNKNOWN_opts_fmt, USAGE_abbrev_txt,
+   TIME_accumed_fmt, UNKNOWN_cmds_txt, UNKNOWN_opts_fmt, VERSION_opts_fmt,
    WORD_abv_mem_txt, WORD_abv_swp_txt, WORD_allcpus_txt, WORD_another_txt,
    WORD_eachcpu_fmt, WORD_exclude_txt, WORD_include_txt, WORD_noneone_txt,
    WORD_process_txt, WORD_threads_txt, WRITE_rcfile_fmt, WRONG_switch_fmt,