withdraw ctags.conf.d patch

In 30b1c6f7a4bff6a1f88bcdf9eac81073056cb58b I introduced code
which loads option files under
/etc/ctags.conf.d, /usr//local/etc/ctags.conf.d and ~/.ctags.d
automatically when ctags process starts.

Withdraw the patch here. After learning systemd I have recognized that
there are two purposes for installing option files to a directory: (1)
autoload, a user want to specify a set of option files to be loaded
automatically when ctags starts, and (2) library, a user wants to
stock common (or popular) option files and enable them when needed.

/etc/ctags.conf.d, /usr//local/etc/ctags.conf.d and ~/.ctags.d are
not enough to handle these tow purposes.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
set fishman-ctags own values to PROGRAM_NAME and PROGRAM_URL

To avoid a bug of fishman-ctags being reported to
exuberant-ctags, change the name and url.

TODO: PROGRAM_COPYRIGHT, AUTHOR_NAME and AUTHOR_EMAIL.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
add /usr/share/ctags/{configs,corpora} to {ConfigPathList,CorpusPathList}

All config files and corpus files maintained in as part of fishman-ctags will
go these directory.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
add /etc/ctags/{configs,corpora} to {ConfigPathList,CorpusPathList}

All config files and corpus files introduced or customized by the user site
will go these directory. These directories take precedence over /usr/share/ctags.

Consider following command line:

	 $ ctags --options=mib ...

In this case mib.ctags is searched following directories with following order:

/etc/ctags/configs/mib.ctags
/usr/share/ctags/configs/mib.ctags

If CTAGS_DATA_PATH environment variable is given, it takes precedence over
above built-in two directories.

	 $ CTAGS_DATA_PATH=A:B ctags --options=mib ...

In this case mib.ctags is searched following directories with following order:

A/mib.ctags
B/mib.ctags
/etc/ctags/configs/mib.ctags
/usr/share/ctags/configs/mib.ctags

Data search path can be specified with --data-dir=[+]DIR option, too.
--data-dir takes precedence over above built-in two directories and
the environment variable.

	 $ CTAGS_DATA_PATH=A:B ctags --data-dir=+DIR --options=mib ...

In this case mib.ctags is searched following directories with following order:

DIR/mib.ctags
A/mib.ctags
B/mib.ctags
/etc/ctags/configs/mib.ctags
/usr/share/ctags/configs/mib.ctags

	 $ CTAGS_DATA_PATH=A:B ctags --data-dir=DIR --options=mib ...

In this case mib.ctags is searched just DIR/mib.ctags.
This is useful to write a test case for a parser.

NOTE: --data-dir option affects after loading ~/.ctags.

TODO: .ctags.d under home directory.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
refactor: introduce gethome()

The ways to get home directory are different in platforms.
The knowledge of the difference should be maintained in
a single place.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
add ~/.ctags.d/{configs,corpora} to {ConfigPathList,CorpusPathList}

TODO: MSDOS_STYLE_PATH
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
add "Option library" and "Loading option recursively"

Signed-off-by: Masatake YAMATO <yamato@redhat.com>