build: Enable some modules by default

We don't enable the ECDSA recovery module, because we don't recommend
ECDSA recovery for new protocols. In particular, the recovery API is
prone to misuse: It invites the caller to forget to check the public
key (and the verification function always returns 1).

In general, we also don't recommend ordinary ECDSA for new protocols.
But disabling the ECDSA functions is not possible because they're not
in a module, and let's be honest: disabling ECDSA would mean to ignore
reality blatantly.

doc/CHANGELOG.md

@@ -6,6 +6,9 @@ Each change falls into one of the following categories: Added, Changed, Deprecat
 
 ## [Unreleased]
 
+### Changed
+ - Enable modules schnorrsig, extrakeys and ECDH by default in ./configure
+
 ## [MAJOR.MINOR.PATCH] - YYYY-MM-DD
 
 ### Added/Changed/Deprecated/Removed/Fixed/Security