"#if FOO" still works with simple -DFOO, but gives more flexibility.
Specifically, if user expressed no preference (FOO is not defined),
we can apply reasonable defaults (this is the legitimate use of ifdef).
In short, from now on, please use
#if MG_ENABLE_FOO
instead of
#ifdef MG_ENABLE_FOO
Since we are all used to #ifdef, this change also adds a precommit check
to police this. Specifically, in *.h and *.c files that are Copyright Cesanta,
"ifdef" and "if defined()" are not allowed to be used with macros that contain
ENABLE or DISABLE, unless the like also contains "ifdef-ok".
Hence, if you are sure you want to use ifdef, use this:
#ifdef MG_ENABLE_FOO /* ifdef-ok */
PUBLISHED_FROM=9be829448f53cff575d6cae8b9945fb12531c15a
On my way, fixed a couple of cases where we had `()` in the header, and
non-empty argument list in the source file.
PUBLISHED_FROM=5519526cf84e2bbd425a726fcc112fea1a95cbf1
