Release version 2.31.4

 * New GPG Agent built into gnome-keyring-daemon
 * Start building (but not using) new DER parser and writer.
 * Fix building of desktop and service files.
 * Fix problems displaying prompts with certain characters in strings.
 * Fix deadlock on secure memory usage.
 * Refactor the way prompting works for PKCS#11 components.
 * Refactor the way testing works and files are named.
 * Implement coverage testing.
 * Cleanup whitespace issues and rename certain modules.
 * Tests can now involve prompts and responses.
 * Fix possible threading race condition in gp11.
 * Fix broken startup when used with gdm and password-less login.
 * Fix checking of uninitialized value in prompting code.