Hi folks,

The RPC2 ./configure process is looking for pkg-config >= 0.9.0,
but it uses two macros PKG_CHECK_MODULES and PKG_CHECK_EXISTS,
which have been introduced later.

_MODULES in 0.12 (or something, changelog wasn't clear) and _EXISTS in 0.18.

I have tried with pkg-config 0.21 and it worked.

Please update this as the insufficently high version results in very cryptic
error message:

"Possibly undefined ... PKG_CHECK_... ", and then later syntax error
near "EXISTS liblua... "..

Cya,
-doc