Fixed sqlite impurity (mostly).

The sqlite configure script guesses whether to enable Tcl support. Apparently,
this guessing finds a Tcl installation in /usr and thus enables Tcl. The
subsequent build fails, however: the compiler doesn't find the <tcl.h> because
/usr is not a default search path. To remedy the problem, the expression now
explicitly specifies --disable-tcl to avoid guessing altogether.

In the same spirit, we furthermore specify the following configure flags, which
represent the defaults that ./configure chooses when left on its own devices:

  --disable-amalgamation
  --enable-threadsafe
  --disable-cross-thread-connections
  --disable-tempstore

svn path=/nixpkgs/trunk/; revision=16184

pkgs/development/libraries/sqlite/default.nix

@@ -15,6 +15,11 @@ stdenv.mkDerivation rec {
   configureFlags = ''
     --enable-load-extension
     ${if static then "--disable-shared --enable-static" else ""}
+    --disable-amalgamation
+    --enable-threadsafe
+    --disable-cross-thread-connections
+    --disable-tcl
+    --disable-tempstore
     --with-readline-inc=-I${readline}/include
   '';