package pthreads-w32: fix for shared build

- Only patch header files to force static build when we are actually
  running a static build.
- Install DLL into bin and stub .a into lib for shared.
Package boost: Enable shared builds
Package lcms1: Enable shared builds
Package gnutls: Fix export for shared build
package hdf5: remove libtool workaround (actually a pthreads build issue)