Add script to bump version

The version must now be bumped at 4 different places. Add a script to
bump automatically:

    ./bump_version 1.23.4

bump_version

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+#
+# This script bump scrcpy version by editing all the necessary files.
+#
+# Usage:
+#
+#     ./bump_version 1.23.4
+#
+# Then check the diff manually to confirm that everything is ok.
+
+set -e
+
+if [[ $# != 1 ]]
+then
+    echo "Syntax: $0 <version>" >&2
+    exit 1
+fi
+
+VERSION="$1"
+
+a=( ${VERSION//./ } )
+MAJOR="${a[0]:-0}"
+MINOR="${a[1]:-0}"
+PATCH="${a[2]:-0}"
+
+# If VERSION is 1.23.4, then VERSION_CODE is 12304
+VERSION_CODE="$(( $MAJOR * 10000 + $MINOR * 100 + "$PATCH" ))"
+
+echo "$VERSION: major=$MAJOR minor=$MINOR patch=$PATCH [versionCode=$VERSION_CODE]"
+sed -i "s/^\(\s*version: \)'[^']*'/\1'$VERSION'/" meson.build
+sed -i "s/^\(\s*versionCode \).*/\1$VERSION_CODE/;s/^\(\s*versionName \).*/\1\"$VERSION\"/" server/build.gradle
+sed -i "s/^\(SCRCPY_VERSION_NAME=\).*/\1$VERSION/" server/build_without_gradle.sh
+sed -i "s/^\(\s*VALUE \"ProductVersion\", \)\"[^\"]*\"/\1\"$VERSION\"/" app/scrcpy-windows.rc
+echo done