0.10.0

Added

• Add -z, --silent option for beep prevention (old Debian patch).
• Add -p, --pointer option for capturing the mouse pointer.
• Add SPDX license identifiers (this software uses MIT-feh license).
• Add Clang static analysis to CI.

Changed

• Fix segfault when using $t special string in the filename.
• Use .png extension when no file extension is passed.
• Fix several static analysis issues and add Clang static analysis to CI.
• Start relicensing new changes to OSI-approved MIT license.