Auto Formatting with clang-format-6.0 (#727)

* Add clang-format

* Auto-format AlphaFilter and RingBuffer

* Update to tab=8spaces

* Allow for 120 width

tools/format.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+do_format=$1
+files_to_format="""
+EKF/AlphaFilter.hpp
+EKF/RingBuffer.h
+"""
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+if ! hash clang-format-6.0
+then
+    echo -e ${RED}Error: No clang-format-6.0 installed${NC}
+    exit 1
+fi
+
+if [[ $do_format -eq 1 ]]
+then
+    # formatting
+    clang-format-6.0 -i -style=file ${files_to_format}
+    echo -e ${GREEN}Formatting finished${NC}
+else
+    # checking format...
+    clang-format-6.0 -style=file  -output-replacements-xml ${files_to_format} | grep -c "<replacement " > /dev/null
+    if [[ $? -eq 0 ]]
+    then
+        echo -e ${RED}Error: need to format${NC}
+        echo -e ${YELLOW}From cmake build directory run: 'make format'${NC}
+        exit 1
+    fi
+    echo -e ${GREEN}no formatting needed${NC}
+    exit 0
+fi