This should fix #111.

[skip ci]

See #103.

Fix readlink for os x [skip ci]

Adds -no-hs-main to iservBin

Fixes #102. But does not *yet* include the generation of the wrapper script.

This should fix #104.

Rework Travis CI script

- Move all .travis/*.sh functionality directly into .travis.yml
- Install Alex/Happy from PPA instead of compiling them by hand
- Skip Shake progress indicators, as they're rather useless
  on clean-slate Travis builds, and clutter up the log
- Don't use a Cabal sandbox for building so Travis can share
  $HOME/.cabal
- boot/configure only after the Shake build system is in place,
  otherwise some required *.in files are not converted, and
  Shake fails

Wrap ghc-stage2

Adds derivedConstantsDependencies for rts

Fix #96 (c.f. #57 for stage1)

Fixes #90. We need to force inlining for rts to compile and not end up with missing symbols.

Fix #88. <gmp.h> is imported by libraries/integer-gmp/cbits/wrappers.c, hence the dependency
generation with GccM, requires gmp.h to be available. We therefore add it to the
generated dependencies.

Building rts depends on derived constants, as we can not rely on the compiler to be build prior to rts,
as we build rts with gcc, and hence do not depend on ghc, we need to have rts depend on the derived
constants. This fixes #94. However, if we are going to build rts with the stage1 ghc, this should not be
an issue anymore (see #90), as derived constants would be build then anyway. Yet I do not see any
problem with explicilty noting down the derived constants dependency for rts.

Travis CI using dirty tricks