Fix basename issue and simplify code

[syohex]

basename command cannot take multiple arguments in POSIX specification.
Coreutils version has --multiple option however it is not portable.
So use zsh :t modifier instead. You can also avoid this issue by using xargs -n1 however it makes slow.

Following error occurs if user installs multiple tbls sub-commands

 basename: extra operand ‘/home/shohei/bin/tbls-foo’

Reference about :t modifier

• http://zsh.sourceforge.net/Doc/Release/Expansion.html#Modifiers

t [ digits ]
Remove all leading pathname components, leaving the final component (tail). This works like ‘basename’. Any trailing slashes are first removed.

[k1LoW]

@syohex WOW !!!! THANK YOU !!!!