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, 2 insertions, 2 deletions

diff --git a/src/kakrc b/src/kakrc
index 4fc8cd37..27e4e289 100644
--- a/src/kakrc
+++ b/src/kakrc
@@ -1,5 +1,5 @@
-hook global WinCreate .* addhl regex \h+(?=\n) default red
-hook global WinCreate .* addhl number_lines
+hook global WinCreate .* %{ addhl regex \h+(?=\n) default red }
+hook global WinCreate .* %{ addhl number_lines }
 
 runtime rc/cpp.kak
 runtime rc/kakrc.kak