Implement option class inheritance

For now multiple, non-virtual inheritance is supported. An option class
can now also be declared abstract using the class c = 0 {...}; syntax.
New option, --exclude-base, controls whether base class information is
present in usage and documentation.

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/inheritance/test.std b/tests/inheritance/test.std
new file mode 100644
index 0000000..4c93225
--- /dev/null
+++ b/tests/inheritance/test.std
@@ -0,0 +1,4 @@
+--very-long-flag  Long flag.
+-i <num>          Integer.
+-s <str>          Short string.
+--string <str>    Long string.