luarocks: support more usage

better support for luarocks in a shell (helpful to develop on luarocks).
Also adds unpacker for src.rock/rockspec files.
Also allows to use luarocks to build cmake based rocks.

pkgs/development/tools/misc/luarocks/setup-hook.sh

@@ -0,0 +1,20 @@
+unpackCmdHooks+=(_trySourceRock)
+unpackCmdHooks+=(_tryRockSpec)
+
+_tryRockSpec() {
+    if ! [[ "$curSrc" =~ \.rockspec$ ]]; then return 1; fi
+}
+
+_trySourceRock() {
+
+    if ! [[ "$curSrc" =~ \.src.rock$ ]]; then return 1; fi
+
+    export PATH=${unzip}/bin:$PATH
+
+    # luarocks expects a clean <name>.rock.spec name to be the package name
+    # so we have to strip the hash
+    renamed="$(stripHash $curSrc)"
+    cp "$curSrc" "$renamed"
+    luarocks unpack --force "$renamed"
+}
+