compiler: relicense to public domain.

We really want everyone to be using these; establishing conventions
helps all code, so make it the most liberal license possible.  It's
all my code, so I can do this unilaterally.

ccan/compiler/LICENSE

@@ -1 +0,0 @@
-../../licenses/LGPL-3

ccan/compiler/_info

@@ -21,7 +21,7 @@
  * - IS_COMPILE_CONSTANT
  *	For using different tradeoffs for compiletime vs runtime evaluation.
  *
- * License: LGPL (v3 or any later version)
+ * License: Public Domain
  * Author: Rusty Russell <rusty@rustcorp.com.au>
  *
  * Example:

ccan/md4/LICENSE

@@ -1 +0,0 @@
-../../licenses/LGPL-2.1