added "break" and "continue" statements

a LoopState was added to the CCompilerState struct which keeps track of breaks, start chunk index, and the start scope of the active loop.
Also, break.cosmo was added to the examples directory, 'continue' and 'break' work as expected.

src/clex.c

@@ -5,6 +5,8 @@
 
 CReservedWord reservedWords[] = {
     {TOKEN_AND, "and", 3},
+    {TOKEN_BREAK, "break", 5},
+    {TOKEN_CONTINUE, "continue", 8},
     {TOKEN_DO, "do", 2},
     {TOKEN_ELSE, "else", 4},
     {TOKEN_ELSEIF, "elseif", 6},