adding tree iters. This should fix missing symbols sometimes.
Use TMTag instead of GeanySymbol so the symbol tree can read the
scope without parsing it (fixes problems with '.' characters in tag
names for e.g. HTML).
Free tag list straight after use, instead of next time the list is
generated.
Use TMTag pointer tree model column instead of line number.
Fix not allowing a leading underscore when using scope name prefix.
Remember parent tree iter for a tag if it is used for a child tag's
scope, rather than just for tags of a certain type. This should be
more flexible for various filetypes.
Various symbol-tree code refactoring.



git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/branches/symbol-tree@3166 ea778897-0a13-0410-b9d1-a72fbfd435f5