Link zlib witb bootloader statically on Solaris
Ensure we are pulling QtWebkitWidgets
Merge pull request #153 from lvillani/qt5-webkitwidgets

Ensure we are pulling QtWebkitWidgets.
add hook for certifi
Merge pull request #154 from m1keil/develop

Add hook for certifi.
Merge pull request #156 from dvitonis/Link-zlib-statically-bootloader-solaris

Link zlib witb bootloader statically on Solaris.
Shortly document option ``append_pkg`` and add test-case.
Fiy a typo.
Fix #1070: Need to acquire import lock when testing for ZlibArchive.
Merge pull request #1075 from matysek/develop

Fixed OSX code signing and some code cleanup.
Make pyi_importers store sys.prefix locally

Otherwise, they may fail if sys.prefix is changed.
Plus, this makes possible to call pyi_importers with a temporarily changed
sys.prefix to point to another temporary directory.