omnitrace-install.py (#221)

- omnitrace-install.py will be uploaded as a release asset
- script simplifies selecting the correct installer script

scripts/write-omnitrace-install.cmake

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.8)
+
+if(NOT DEFINED OMNITRACE_VERSION)
+    file(READ "${CMAKE_CURRENT_LIST_DIR}/../VERSION" FULL_VERSION_STRING LIMIT_COUNT 1)
+    string(REGEX REPLACE "(\n|\r)" "" FULL_VERSION_STRING "${FULL_VERSION_STRING}")
+    string(REGEX REPLACE "([0-9]+)\.([0-9]+)\.([0-9]+)(.*)" "\\1.\\2.\\3"
+                         OMNITRACE_VERSION "${FULL_VERSION_STRING}")
+endif()
+
+if(NOT DEFINED OUTPUT_DIR)
+    set(OUTPUT_DIR ${CMAKE_CURRENT_LIST_DIR})
+endif()
+
+message(
+    STATUS
+        "Writing ${OUTPUT_DIR}/omnitrace-install.py for omnitrace v${OMNITRACE_VERSION}")
+
+configure_file(${CMAKE_CURRENT_LIST_DIR}/../cmake/Templates/omnitrace-install.py.in
+               ${OUTPUT_DIR}/omnitrace-install.py @ONLY)