[COOK-3402] When the ext_dir setting is present, configure php properly for the source recipe

Signed-off-by: Seth Vargo <sethvargo@gmail.com>
[COOK-2926] Use grep_for_version to detect if package is pear/pecl

Signed-off-by: Seth Vargo <sethvargo@gmail.com>
[COOK-3638] Fix download location

Signed-off-by: Seth Vargo <sethvargo@gmail.com>