Remove launcher scripts from git

For a while now we have been mandating that `bootstrap` is run before
emscripten can be used.  This change removes most of the launcher
scripts from git (since we can rely on bootstrap to create them).

This helps clean up the top level directory.

I've left `emcc` and `em++` launchers in source control.  If anyone runs
these without first running `bootstrap` it will ask them to first run
`bootstrap`.

Author: sbc100

.gitignore

@@ -30,8 +30,50 @@ coverage.xml
 # Test output
 /out/
 
-# All the ps1 files are generated by bootstrap...
+# Windows ps1 launchers (created by ./tools/maint/create_entry_points.py)
 *.ps1
 # ...except the templates.
 !/tools/run_python.ps1
 !/tools/run_python_compiler.ps1
+
+# Shell scripts (created by ./tools/maint/create_entry_points.py)
+em-config
+emar
+embuilder
+emcmake
+emconfigure
+emdump
+emdwp
+emmake
+emnm
+emprofile
+emranlib
+emrun
+emscan-deps
+emscons
+emsize
+emstrip
+emsymbolizer
+tools/file_packager
+tools/webidl_binder
+
+# Windows .bat files (created by ./tools/maint/create_entry_points.py)
+em-config.bat
+emar.bat
+embuilder.bat
+emcmake.bat
+emconfigure.bat
+emdump.bat
+emdwp.bat
+emmake.bat
+emnm.bat
+emprofile.bat
+emranlib.bat
+emrun.bat
+emscan-deps.bat
+emscons.bat
+emsize.bat
+emstrip.bat
+emsymbolizer.bat
+tools/file_packager.bat
+tools/webidl_binder.bat

bootstrap

@@ -11,8 +11,8 @@
 # To make modifications to this file, edit `tools/run_python.sh` and then run
 # `tools/maint/create_entry_points.py`
 
-# $PYTHON -E will not ignore _PYTHON_SYSCONFIGDATA_NAME an internal
-# of cpython used in cross compilation via setup.py.
+# $PYTHON -E does not ignore _PYTHON_SYSCONFIGDATA_NAME, an internal of cpython
+# used in cross compilation via setup.py, so we unset it explicitly here.
 unset _PYTHON_SYSCONFIGDATA_NAME
 
 if [ -z "$PYTHON" ]; then

cmake/Modules/Platform/Emscripten.cmake

@@ -60,7 +60,7 @@ endif()
 # Locate where the Emscripten compiler resides in relative to this toolchain file.
 if (NOT DEFINED EMSCRIPTEN_ROOT_PATH)
   get_filename_component(GUESS_EMSCRIPTEN_ROOT_PATH "${CMAKE_CURRENT_LIST_DIR}/../../../" ABSOLUTE)
-  if (EXISTS "${GUESS_EMSCRIPTEN_ROOT_PATH}/emranlib")
+  if (EXISTS "${GUESS_EMSCRIPTEN_ROOT_PATH}/emranlib.py")
     set(EMSCRIPTEN_ROOT_PATH "${GUESS_EMSCRIPTEN_ROOT_PATH}")
   else()
     # If not found by above search, locate using the EMSCRIPTEN environment variable.