We fix GNU configure script stupidity by directly replacing the stock
install-sh script provided by the software with the BSD install-compatible
sysutils/install-sh script.
A new package-settable variable comes to life:
INSTALL_SH_OVERRIDE is a list of files relative to WRKSRC which
should be overridden by the install-sh script from
sysutils/install-sh. If not defined or set to "no", then
no files are overridden.
Possible values: no, defined, undefined.
Default value: defined when GNU_CONFIGURE is defined, undefined
otherwise.
Get rid of the install_sh tool, which is no longer needed.
