add 'getlib' to get vendor library functions

[icasimpan]

command sample:

shcf_cli getlib <project_name> shcf-lib/abs_value:v1.0

underneath, it would be (tag abs_value-v1.0 in https://github.com/icasimpan/shcf-lib):

git clone --branch abs_value-v1.0 https://github.com/icasimpan/shcf-lib

or, without the ":v1.0" specified at the end, latest tag will be used and is always the same as branch "stable/abs_value in https://github.com/icasimpan/shcf-lib.

.shcf-vendor.lock - lock file similar in purpose to composer.json.lock
create a

shcf-vendor.lock

with format:

          [repodomain.ext/username/]<libname>:vX.Y:sha256sum
          [repodomain.ext/username] -> defaults to github.com/icasimpan/shcf-lib

---> so that external repositories can be made like github.com/maeng/shcf-lib/

in "getlib", make sure:

      stable/<lib_name>
                \- lib/<lib_name>.bash.inc    => goes to lib/
                \- etc/init.conf                 => app_defs.conf
                \- etc/binaries.conf         => binaries.conf (filter out existing one)
                \- dependencies.cfg       => dependency libraries of <lib_name>.in each line
                \- version_hash.cfg.        => [repodomain.ext/username/]<libname>:vX.Y:<hash>

where hash is taken as follows:

~$ for x in $(find ./shcf-lib/abs_value -type f|grep -v .git|grep -v version_hash.cfg); do sha256sum $x; done|sha256sum|cut -d' ' -f1
17eafc47d1e9919168aeaaaef1038a1bf953a7c8adaf4731453e9559593c9b26

Libraries are written into 'vendor' folder in shcf core for audit purposes but copied into corresponding project's 'lib' directory.

[icasimpan]

Initial implementation committed to branch 'getlib'. Check the TODO in

core/lib/create_getlib.bash.inc
and this was unimplemented yet:
shcf-vendor.lock
NOTE: it shouldn't be hidden so no dot as first character of vendor-lock name