- Update version to 1.26.0
* update translations
* travis-Ci: use libera.chat as notification server
* update copyright to 2021
* add wayland support
* port to GtkApplication
* Use GtkBuilder for preferences dialog
* openfiles: g_memdup is dreprecated from glib 2.68
* smooth_refresh: comparison of unsigned expression in '< 0' is always false
* gsm_color_button: macro "__GSM_COLOR_BUTTON_C__" is not used
* proctable: Function 'proctable_free_table' used prior to declaration
* i18n: use _() macro instead of gettext
* i18n: Do not collect the translation for Icon
* build: display package name and version in configure summary
* build: Use PACKAGE_URL variable
* procdialogs: Do not use deprecated gtk_image_new_from_stock
* Show subvol mount option on GNU/Linux
* sysinfo: avoid adding a device more than once such as for brtfs
* pretty-table: prefer GIO to get application icons
- Drop mate-system-monitor-glib-2.54.patch, no longer support glib 2.54