[Req] More navigation

[ArsenShnurkov]

So, i have a string and a tree of matches.

1. I want to have the possibility to get match by offset in the string (the problem is that there are several similar objects exists for one integer offset);
2. I want to have the possibility to move from one match to adjancent one (i.e., my file consists from sections and intersection separators, I want to obtain the nearest separator after section which I hold now);
3. i don't understood how to move up in the Matches tree (without traversing the whole tree again).