Latvian: 1) added some extra things that are used by the Attempto grammar; 2) added notpresent tags; 3) compiles with Setup.hs and lib/src/Make.hs

src/api/SymbolicLav.gf

@@ -0,0 +1,5 @@
+--# -path=.:present:mathematical:prelude:../latvian
+
+resource SymbolicLav = Symbolic with
+  (Symbol = SymbolLav),
+  (Grammar = GrammarLav) ;