Initial commit of saving a game

Includes:
- inventory
- money
- current weapon
- location
Fixes loading save game after quit to menu
For real - loading of saved games is 'better'
Deselect a weapon when saving
re-equip your weapon post-save
[WIP] Added initial load menu
Addresses #1031 and #1287

Addresses #1031 and #1287
adds "hidden" chest and small change to breakable_block
added boulder and support for larger breakable block
Cleaned up the load menu a little

Also added the level name (if appropriate) to the menu.
Merge branch 'master' into hidden-chest
Initial commit of saving a game

Includes:
- inventory
- money
- current weapon
- location
Fixes loading save game after quit to menu
For real - loading of saved games is 'better'
Deselect a weapon when saving
re-equip your weapon post-save
[WIP] Added initial load menu
Addresses #1031 and #1287

Addresses #1031 and #1287
Cleaned up the load menu a little

Also added the level name (if appropriate) to the menu.
merging from main