Merge branch master into staging to fix eval error

This fixes the eval error of the small (and "big"?) NixOS test set that
was fixed in 1088f05 & eba8f542.

pkgs/servers/sql/mariadb/default.nix

@@ -15,7 +15,7 @@ let # in mariadb # spans the whole file
 
 libExt = stdenv.hostPlatform.extensions.sharedLibrary;
 
-mytopEnv = perl.withPackages (p: with p; [ DataDumper DBDmysql DBI TermReadKey ]);
+mytopEnv = perl.withPackages (p: with p; [ DBDmysql DBI TermReadKey ]);
 
 mariadb = server // {
   inherit client; # MariaDB Client

pkgs/servers/sql/postgresql/ext/periods.nix

@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "periods";
-  version = "1.1";
+  version = "1.2";
 
   src = fetchFromGitHub {
     owner = "xocolatl";
     repo = pname;
     rev = "v${version}";
-    sha256 = "0gdnlbh7kp7c0kvsrri2kxdbmm2qgib1qqpl37203z6c3fk45kfh";
+    sha256 = "13aix61qzlb7cs042dz4x0z4sc2xayg4nzi2cks46zibxm5i4gzm";
   };
 
   buildInputs = [ postgresql ];

pkgs/servers/sql/postgresql/ext/pg_similarity.nix

@@ -18,7 +18,8 @@ stdenv.mkDerivation {
   '';
 
   meta = {
-    description = ''
+    description = "An extension to support similarity queries on PostgreSQL";
+    longDescription = ''
        pg_similarity is an extension to support similarity queries on PostgreSQL. The implementation
        is tightly integrated in the RDBMS in the sense that it defines operators so instead of the traditional
        operators (= and <>) you can use ~~~ and ~!~ (any of these operators represents a similarity function).

pkgs/servers/sql/postgresql/ext/pgtap.nix

@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
   '';
 
   meta = with stdenv.lib; {
-    description = "pgTAP is a unit testing framework for PostgreSQL";
+    description = "A unit testing framework for PostgreSQL";
     longDescription = ''
       pgTAP is a unit testing framework for PostgreSQL written in PL/pgSQL and PL/SQL.
       It includes a comprehensive collection of TAP-emitting assertion functions,