When php is installed on the host system, then the configure tries
to obtain from this binary whether some extensions are available.
This prevents the cross build when the desired extensions are not
present - which is the usual case.

So add a patch to prevent configure from doing this - we give
this information via environment variable during build already.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

- remove hack to find required packages: when php5-pecl-{raphf,propro}
  was built in paralle, then the hack could not determine which build
  directory must be used; this was resolved by a previous commit, both
  packages now install their header files in the staging area so that
  this pecl module will find it properly

- refine build dir to avoid collision with (possible) php5 package variant

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

Quote:
This PHP HTTP extension aims to provide a convenient and powerful
set of functionality for one of PHPs major applications:
it eases handling of HTTP urls, headers and messages, provides
means for negotiation of a client's preferred content type,
language and charset, as well as a convenient way to send any
arbitrary data with caching and resuming capabilities.
It provides powerful request functionality with support for
parallel requests.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>