CommandManager: rework command parser

a new type of strings is supported inspired by the ruby strings.
%<delimiter>content<delimiter>, if opening delimiter is one of
([{<, then closing delimiter is the matching )]}> and balanced
delimiters in the string needs not to be escaped, else the closing
delimiter is the same as the opening one.

shell expansion is available through %sh<delimiter>command<delimiter>
syntax.

Command flags have been removed, as these strings provide proper nesting
support, so now, you can for example do:

def command %{ echo %sh{ ls } }

1 files changed, 10 insertions, 7 deletions

diff --git a/src/rc/diff.kak b/src/rc/diff.kak
index 8a9a390f..434026ab 100644
--- a/src/rc/diff.kak
+++ b/src/rc/diff.kak
@@ -1,11 +1,14 @@
-hook global BufCreate .*\.(diff|patch) \
+hook global BufCreate .*\.(diff|patch) %{
     setb filetype diff
+}
 
-hook global WinSetOption filetype=diff \
-    addhl group diff-highlight; \
-    addhl -group diff-highlight regex "^\+[^\n]*\n" green default; \
-    addhl -group diff-highlight regex "^-[^\n]*\n" red default; \
-    addhl -group diff-highlight regex "^@@[^\n]*@@" cyan default;
+hook global WinSetOption filetype=diff %{
+    addhl group diff-highlight
+    addhl -group diff-highlight regex "^\+[^\n]*\n" green default
+    addhl -group diff-highlight regex "^-[^\n]*\n" red default
+    addhl -group diff-highlight regex "^@@[^\n]*@@" cyan default
+}
 
-hook global WinSetOption filetype=(?!diff).* \
+hook global WinSetOption filetype=(?!diff).* %{
     rmhl diff-highlight
+}