run installJavaLib also in postCopy

I think installJavaLib also needs to be run in postCopy,
though still untested.
Restored missing Int to Integer conversion codegens
Merge branch 'restored-itnative-codegen' of https://github.com/Ralith/Idris-dev into StrLenRegressionTest
Regression test for StrLen.
Restored missing Int to Integer conversion codegens
Remove redundant and erroneous codegen case
Merge pull request #387 from Ralith/restored-itnative-codegen

Restored missing Int to Integer conversion codegens
Merge pull request #388 from JanBessai/StrLenRegressionTest

StrLen regression test
Merge pull request #384 from JanBessai/JavaRepairs

Rewritten and much better Java backend + All tests pass again
Merge pull request #382 from juhp/patch-2

run installJavaLib also in postCopy
Make LLVM optional but the default
javascript: get more out of google closure
javascript: fixed bug introduced through primitive unification
javascript: remove duplicate test
javascript: factor out runtime namespace
javascript: optimize some primitive functions
Vector FFI and bitcasts
Cleanup
javascript: remove broken optimization
javascript: fix names