nwg-launchers v0.7.0

This release adds limited support for XDG Desktop Menu Categories (see README for details), nwgbar CSS styling, and fixes a number of issues:

• XDG Desktop Menu Categories #198
• Allow to define CSS classes in nwgbar JSON file #195
• Saturate icon size if it's off the allowed range (16-2048) #188
• Use /tmp if XDG_RUNTIME_DIR is not defined and /var/run/user/UID not exists #192
• Allow for ~ in the beginning of Exec= value #205

Special thanks:

• FreeBSD build fix @jbeich
• Support for changing GTK themes @jovanlanik
• CSS fix @MarkusVolk