Improve highlighting of Kakrc string regions

Unfortunately Strings that start with a quoted quote (like '''str')
are still incorrectly highlighted, a deeper refactoring of the regions
highlighter will be necessary.

rc/core/kakrc.kak

@@ -13,8 +13,8 @@ hook global BufCreate (.*/)?(kakrc|.*.kak) %{
 
 add-highlighter shared/ regions -default code kakrc \
     comment (^|\h)\K# $ '' \
-    double_string %{(^|\h)\K"} %{(?<!")("")*"(?!")} '' \
-    single_string %{(^|\h)\K'} %{(?<!')('')*'(?!")} '' \
+    double_string %{(^|\h)\K"} %{"(?!")} %{(?<!")("")+(?!")} \
+    single_string %{(^|\h)\K'} %{'(?!')} %{(?<!')('')+(?!')} \
     shell '(^|\h)\K%?%sh\{' '\}' '\{' \
     shell '(^|\h)\K%?%sh\(' '\)' '\(' \
     shell '(^|\h)\K%?%sh\[' '\]' '\[' \

src/highlighters.cc

@@ -1709,7 +1709,7 @@ struct RegionMatches
                 return end_it;
 
             while (rec_it != recurse_matches.end() and
-                   rec_it->end_coord() <= end_it->begin_coord())
+                   rec_it->end_coord() <= end_it->end_coord())
             {
                 if (not capture or rec_it->capture == *capture)
                     ++recurse_level;