Search for runtime files in shared directory, to support system-wide installation

[vrza]

Check directories relative to the directory the executable is run from.

If runtime files dir is not found under ${exedir}/root/lotus, try searching in ${exedir}/../share/lotus.

This should help support system-wide installation and packaging.

Related to issue #66

[vrza]

@taviso what do you think about this approach?

The location for the default config file can admittedly be nicer, e.g. $PREFIX/share/lotus/123.v10/etc/l123set.cf

[vrza]

Thinking about this further, another approach could be:

• install runtime files, 123 binary, and default config under the same directory tree, e.g. /opt/lotus/123.v10
• man pages installed into a standard dir in MANPATH e.g. /usr/local/share/man/ or /usr/share/man/

Then either:

• install 123 in a standard dir in PATH, e.g. /usr/local/bin/ or /usr/bin/ as a symlink to the 123 binary
• 123 binary resolves the symlink, if invoked through it, to find default config and runtime files

or:

• install 123 in a standard dir in PATH, e.g. /usr/local/bin/ or /usr/bin/ as a symlink to a wrapper shell script that resolves the symlink to find the location of the 123 binary and execs the binary
• 123 binary finds default config and runtime files relative to where it was exec'd from

[vrza]

Discussion related to #20

[taviso]

Sorry for the slow response - I was focused on the keymap issue. This looks good to me, I rolled back the extract script temporarily because of bug reports, as soon as that returns I think this is good to merge.

[vrza]

No rush. I can create a new branch with the fixed extract file and with the unified filesystem approach described above:

${PREFIX}/bin/123
${PREFIX}/share/lotus/123.v10/
${PREFIX}/etc/l123set.cf

[vrza]

@taviso Created a new PR based on current main branch for your convenience:

#70

Some files have been moved around (most notably binary is now built as bin/123) so please test on whatever setup you can. I tested on Linux, works for me in both git directory as well as installed system-wide in /usr/local.

[taviso]

Thank you, closing as #70 has now been merged instead.