for the contents of the exported private key to Phar->setSignatureAlgorithm, and expects the public key to be in
a file named blah.phar.pubkey in the same directory as the phar blah.phar. This works with openssl static or
shared and fails gracefully if openssl is not present without adding a dependency. config.w32 needs updating to match config.m4 [DOC]
this is done by removing zlib/bz2 explicit dependencies because they are unnecessary
we only ever use the stream filter, and the check for existence has
been moved to runtime where it is after startup
Phar is enabled as a shared extension by default in order to allow zlib/bz2 to be built shared. If phar is statically built,
both zlib and bz2 must be statically built in order for phar to use them, so default compile as shared is much more flexible
