Fix a warning.
Make rawSystemStdInOut more verbose on error.
Make it possible to build empty libraries again.

Restores old behaviour broken by @igfoo in
8395c5db800284c9e2b54b5c45b94c4a3bfdfcf2. Fixes #1241.
Trailing newlines.
Make TestSuiteExeV10/TestWithHpc check hpc version.

Fixes #1206.
80-col violations, whitespace.
Fix building of exes that use TH and profiling.

Fixes #1207. Broken by @dcoutts in 02f8eef1c0592ab90238de29c2fe88ec89c85c2f.

Combined with the hpc fix, this makes all tests pass on my machine.
Add a test for #1241.
Merge pull request #1249 from 23Skidoo/issue1241

 Make it possible to build empty libraries again.
Merge pull request #1250 from 23Skidoo/check-hpc-version

Make TestSuiteExeV10/TestWithHpc check hpc version.
Merge pull request #1251 from 23Skidoo/failing-tests

Fix building of exes that use TH and profiling.
don't repeat this four times in the haddocks