CodeSnip Old Code (SVN)

* Extracted code that deals with snippets and snippet lists from USnippets into new DB.USnippet unit.
* Modified affected code accordingly.

Refactoring: Renamed TRoutine, TRoutineEx and TTempRoutine to TSnippet, TSnippetEx and TTempSnippet.

Modified comments in light of change in r1329.

Changed unit name generation so that unit name contains only ASCII characters instead of any character from default ANSI character set since some Delphi have a problem with some ANSI characters.

* Changed to write units as UTF-8 files if source code can't be stored in default ANSI code page. Still uses ANSI default encoding otherwise.
* Ensured that unit names are valid strings in default ANSI encoding to ensure that unit file names contain no Unicode characters (this can make earlier Delphis fail to find file).

Development branch for CodeSnip release 4.

Initial source is a copy of v3.8.4 (r1075).