mpfr: Add description, doc_url and dev_url

mpfr/meta.yaml

@@ -7,14 +7,24 @@ source:
   url: http://www.mpfr.org/mpfr-current/mpfr-3.1.3.tar.bz2
   md5: 5fdfa3cfa5c86514ee4a241a1affa138
 
+build:
+  number: 0
+
 requirements:
   build:
     - gmp
   run:
     - gmp
 
-
 about:
   home: http://www.mpfr.org/
-  license: LGPL
+  license: LGPL (>=3)
+  license_family: LGPL
   summary: The MPFR library is a C library for multiple-precision floating-point computations with correct rounding.
+  description: |
+    The main goal of MPFR is to provide a library for multiple-precision
+    floating-point computation which is both efficient and has a well-defined
+    semantics. It copies the good ideas from the ANSI/IEEE-754 standard for
+    double-precision floating-point arithmetic (53-bit significand).
+  doc_url: http://www.mpfr.org/mpfr-current/mpfr.html
+  dev_url: http://www.mpfr.org/gforge.html