Remove a cross-compile workaround.

ar and ranlib can be easily detected with autoconf.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@380671 f38db490-d61c-443f-a65b-d21fe96a405b
Always check for libm, regardless of configure options.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@380672 f38db490-d61c-443f-a65b-d21fe96a405b
Add support for parallel builds of pjproject.

Also adds proper dependency checking, and direct .a file targets.  We don't
take advantage of this currently, but we will soon.

(issue ASTERISK-20815)


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@380673 f38db490-d61c-443f-a65b-d21fe96a405b