Adapt readpe for the new libpe. Work in progress.
- readpe: Validate directories & sections, and use new libpe functions.
- Fix multiple missing consntess.
readpe: Change some outputs in an attempt to make output parsing easier.

  These ouputs have been changed:
    1. Machine type
    2. Image characteristics
    3. Windows subsystem
    4. Directory names

  I also introduced a compile-time switch to keep output compatibility
  with version 0.6. To enable it, compile pev with:

  $ make CFLAGS="-DLIBPE_ENABLE_OUTPUT_COMPAT_WITH_V06"

  Please, report any inconsistencies you may find.
readpe: Tidy up wrong copy & paste.
readpe: Access internal data using exposed functions.
- Allow to use other compiler using CC env var
Merge pull request #48 from felipensp/clang_build

- Allow to use other compiler using CC env var
Merge branch 'master' of github.com:merces/pev into mmap
Reimplement functions related to import dir.
readpe: Adapt to new SectionCharacteristics.
readpe: Fix output of characteristic name.
Adapt ofs2rva and rva2ofs for the new libpe.
Adapt pehash for the new libpe.
The libpe submodule now refers to the mmap branch.
- The Makefile now uses GNU conventions [1].
- Need to to fix the install rule on Linux.

[1] The GNU coding standards, March 8, 2013.
    http://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
Adapt pesec for the new libpe.
Functions with no parameters should have a `void` on its parameter list.
Fix stack cookies. Revert changes made in 638a078 and re-adapt.
started pescan conversion, only the new cpl analysis is working
pescan: Adapt entropy calculation for the new libpe.