Merge branch 'baagaard/add-release-1.9.8'

* baagaard/add-release-1.9.8:
  Add documentation comment.
  Make scripts executable.
  Try adding clang compiler.

Author: baagaard-usgs

.travis.yml

@@ -4,10 +4,16 @@ sudo: false
 
 language: cpp
 
+# :TODO: @brad Add osx build (need homebrew packages)..
 matrix:
   include:
     - os: linux
       env: LD_LIBRARY_PATH="${DEPS_DIR}/lib:${TARGET_DIR}/lib:${LD_LIBRARY_PATH}"
+      compiler: gcc
+    - os: linux
+      env: LD_LIBRARY_PATH="${DEPS_DIR}/lib:${TARGET_DIR}/lib:${LD_LIBRARY_PATH}"
+      compiler: clang
+
 
 # Limit number of commits in cloning (but keep enough so that 'git describe' works)
 git:
@@ -38,7 +44,7 @@ script:
 
 env:
   global:
-    - MAKE_THREADS=2
+    - MAKE_THREADS=$(nproc)
     - PYTHON_VERSION="2.7"
     - DEPS_DIR="${TRAVIS_BUILD_DIR}/dist/deps"
     - TARGET_DIR="${TRAVIS_BUILD_DIR}/dist/target"