Various bugs with combining push block flags

http://webzoom.freewebs.com/xmuppets...hblocktest.qst
Okay, so in 2.50, you have inherent combo flags, so that way you can make different combinations with the push block flags, like making a push block that can only be moved in 1 horizontal direction and 1 vertical direction, or even a 3-way push block that can be moved in any direction except one.

However, I discovered many problems with this:
1. It can cause under combos left behind by the push blocks to be movable as well.
2. When combining a push block flag that triggers secrets with a push block flag that does not trigger secrets, here's the case:
If the push block flag that triggers secrets is the inherent flag, then it secret triggering is nullified by the push block flag that does not trigger secrets, but if the block flag that does not trigger secrets is the inherent flag, then the push block flag that triggers secrets makes the inherent flag able to trigger secrets as well.
3. When combining a push block flag that only allows the block to be moved once with a push block flag that allows the block to be moved multiple times, here's the case:
If the push block (once) flag is the inherent flag, then its behavior is overridden by the push block (many) flag, but if the push block (many) flag is the inherent flag, then here's the case:
If you move it in any directions specified by the push block (once) flag, then you will not be able to move it in any direction again, but if you move it in any directions specified by the push block (many) flag, you will not be able to move it in any direction specified by the push block (once) flag until you return the block to its original position.

#2 should be fixed.
#1 isn't fixed yet, but I think I can do that.
#3 may be a rewrite issue. I don't see a reasonable fix with the current push block code.

#1 should be fixed now.

Well, 1 and 2 are confirmed fixed; as for 3, if the push block (many) flag is the inherent flag, then here's what the case is now:
If you move it in any directions specified by the push block (once) flag, then you will not be able to move it in any direction again, but if you move it in any directions specified by the push block (many) flag, you will not be able to move it in any direction specified by the push block (once) flag, not even after you return the block to its original position.

I reverted the change that fixed pushable under combos, since it caused other problems. I don't see a reasonable way to fix it, so it'll just have to remain an issue for now. #2 should still be fixed.