update package sqlite
update package vmime
update package openssl
update package libpng
update package vmime
update package vmime
update package gettext
package qtsystems: fix lib casing
package qtsystems: fix gcc 4.9 compatibility
package exiv2: enable shared build
update package dbus
update package libpng
update package qtsystems
update package qtsystems
mxe-activate: use compgen -e for variable list instead of env
qtserialport_qt4: use package info of qtserialport

This fixes downloading this package.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Use libusb instead of the deprecated libusbx

libusbx was a fork of libusb with compatible API. Now it is fully merged
into libusb, so use the latter instead.

Fixes #415.

Commit message amended by Timothy Gu.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add packages tcl and tk

Closes #410 and #412.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
mxe-activate: fix variable matching
packages cairo fontconfig freetype harbuzz: bootstrap build for mutual dependencies