Fixes #1 - Add OSX support

- Support to OSX finished, thanks to MESH Consultants Inc.
- Added a new possible failure `CR_BAD_IMAGE` in case the binary file is stil not ready even if its timestamp changed. This could happen if generating the file (compiler or copying) was slow.
- Windows: Fix issue with too long paths causing the PDB patch process to fail, causing the reload process to fail (reported by Ricard Pillosu).
- **Possible breaking change:** Fix rollback flow. Before, during a rollback (for any reason) two versions were decremented one-shot so that the in following load, the version would bump again getting us effectively on the previous version, but in some cases not related to crashes this wasn't completely valid (see `CR_BAD_IMAGE`). Now the version is decremented one time in the crash handler and then another time during the rollback and then be bumped again. A rollback due an incomplete image will not incorrectly rollback two versions, it will continue at the same version retrying the load until the image is valid (copy or compiler finished writing to it). This may impact current uses of `cr` if the `version` info is used during `CR_UNLOAD` as it will now be a different value.

.travis.yml

@@ -4,6 +4,7 @@ language: cpp
 compiler: gcc
 os: 
     - linux
+    - osx
 addons:
   apt:
     sources:
@@ -17,10 +18,10 @@ addons:
       - libglu1-mesa-dev
       - xorg-dev
 script:
-    - sudo ln -s /usr/bin/gcc-7 /usr/local/bin/gcc
-    - sudo ln -s /usr/bin/g++-7 /usr/local/bin/g++
-    - export CC=/usr/bin/gcc-7
-    - export CXX=/usr/bin/g++-7
+    - if [¨$TRAVIS_OS_NAME¨ == ¨linux¨ ]; then sudo ln -s /usr/bin/gcc-7 /usr/local/bin/gcc
+    - if [¨$TRAVIS_OS_NAME¨ == ¨linux¨ ]; then sudo ln -s /usr/bin/g++-7 /usr/local/bin/g++
+    - if [¨$TRAVIS_OS_NAME¨ == ¨linux¨ ]; then export CC=/usr/bin/gcc-7
+    - if [¨$TRAVIS_OS_NAME¨ == ¨linux¨ ]; then export CXX=/usr/bin/g++-7
     - gcc -v && g++ -v && cmake --version
     - git --version
     # setup and check fips