Fix shell variables

Fix shell variables that where style "windows styled"

linux/mc_start.sh

@@ -6,7 +6,7 @@ MC_DIR=~/.minecraft
 # Are stored here...
 # saves/, resourcepacks/ and screenshots/ dirs
 # and options.txt and servers.dat files
-GAME_DIR=%MC_DIR
+GAME_DIR=$MC_DIR
 
 # Assets location
 ASSETS_DIR=$MC_DIR/assets
@@ -38,7 +38,7 @@ net.minecraft.client.main.Main \
 --username $PLAYER_NAME \
 --version $GAME_VERSION \
 --accessToken 0 --userProperties {} \
---gameDir %GAME_DIR% \
+--gameDir $GAME_DIR \
 --assetsDir $ASSETS_DIR \
 --assetIndex $ASSETS_INDEX \
 --width $WINDOW_W --height $WINDOW_H