Fix and simplify building docs and schemas (#441)

Fix and simplify building docs and schemas

1. Do an in-source build of derived schemas instead of building into build and checking that the files match.
2. Fix paths of installed docs, which were failing on me
3. Consolidate docs into same cmakelists that generates schema files
4. Trang is usually available as an executable, so find it with find_program.
5. Add doc dependencies to package.xml

Signed-off-by: Dan Rose <dan@digilabs.io>

.travis.yml

@@ -45,7 +45,7 @@ linux_gcc8: &linux_gcc8
     apt:
       update: true
       sources: [ ubuntu-toolchain-r-test ]
-      packages: [ gcc-8 g++-8 ]
+      packages: [ gcc-8, g++-8, trang ]
   before_install:
     - eval "export CC=gcc-8"
     - eval "export CXX=g++-8"
@@ -61,6 +61,7 @@ linux_clang: &linux_clang
   addons:
     apt:
       update: true
+      packages: [ trang ]
   before_install:
     - eval "export CC=clang"
     - eval "export CXX=clang++"
@@ -74,7 +75,7 @@ osx_xcode: &osx_xcode
   compiler: clang
   addons:
     homebrew:
-      packages: [ python3 ]
+      packages: [ python3, trang ]
   before_install:
     - eval "export CC=clang"
     - eval "export CXX=clang++"
@@ -88,7 +89,7 @@ osx_xcode9: &osx_xcode9
   osx_image: xcode9
   addons:
     homebrew:
-      packages: [ python3 ]
+      packages: [ python3, trang ]
       # Homebrew must be updated before packages can be installed on outdated
       # macOS images. The update process unfortunately takes a VERY long time
       # and can even cause Travis to terminate the build. Travis caching is
@@ -195,6 +196,7 @@ script:
   - mkdir build
   - cd build
   - conan install -b missing -s arch=${ARCH} -s build_type=${BUILD_TYPE} ..
+  - which trang && BUILD_SCHEMA=1 || BUILD_SCHEMA=0
   - cmake -DCMAKE_BUILD_TYPE=${BUILD_TYPE}
           -DCMAKE_INSTALL_PREFIX=${INSTALLPREFIX}
           -DUSE_SANITIZER=${ASAN}
@@ -202,9 +204,11 @@ script:
           -DENABLE_LIFESPAN=${LIFESPAN}
           -DENABLE_DEADLINE_MISSED=${DEADLINE}
           -DBUILD_TESTING=on
+          -DBUILD_SCHEMA=${BUILD_SCHEMA}
           -DWERROR=on
           -G "${GENERATOR}" ..
-  - case "${GENERATOR}" in
+  - |
+    case "${GENERATOR}" in
       "Unix Makefiles")
         ${SCAN_BUILD} cmake --build . --config ${BUILD_TYPE} --target install -- -j 4
         ;;
@@ -216,14 +220,20 @@ script:
         ;;
     esac
   - CYCLONEDDS_URI='<CycloneDDS><Domain><Internal><EnableExpensiveChecks>all</EnableExpensiveChecks><LivelinessMonitoring>true</LivelinessMonitoring></Internal><Tracing><Verbosity>config</Verbosity><OutputFile>stderr</OutputFile></Tracing></Domain></CycloneDDS>' ctest -j 4 --output-on-failure -T test -E '^CUnit_ddsrt_random_default_random$' -C ${BUILD_TYPE}
-  - if [ "${ASAN}" = "none" ]; then
+  - |
+    if [ "${ASAN}" = "none" ]; then
       ${SHELL} ../src/tools/ddsperf/sanity.bash;
     fi
-  - if [ "${ASAN}" != "none" ]; then
+  - |
+    if [ "${ASAN}" != "none" ]; then
       CMAKE_LINKER_FLAGS="-DCMAKE_LINKER_FLAGS=-fsanitize=${USE_SANITIZER}";
       CMAKE_C_FLAGS="-DCMAKE_C_FLAGS=-fsanitize=${USE_SANITIZER}";
     fi
   - cd ..
+  - |
+    if [ ${BUILD_SCHEMA} ]; then
+      git diff --exit-code; # check that no files (e.g. generated schemas) are changed
+    fi
   - mkdir helloworld_build
   - cd helloworld_build
   - cmake -DCMAKE_PREFIX_PATH=${INSTALLPREFIX}