Added .gitignore and README

.gitignore

+# Ignore all
+*
+
+# Unignore all with extensions
+!*.*
+
+# Unignore all dirs
+!*/
+
+!Makefile
+
+*.cub
+*.o
+*.so
+*.so.*
+*.a
+moc_*
+*.pb.*
+*.lbl
+*.img
+
+!TestPreferences
+
+print.prt
+
+object_script.*.Release
+object_script.*.Debug
+*_plugin_import.cpp
+*.moc
+ui_*.h
+
+*/3rdParty/*
+!*/3rdParty/Makefile
+
+*/inc/*
+
+*/bin/*
+
+*/lib/*
+
+*/tsts/*/input/*
+*/tsts/*/truth/*
+*/tsts/*/output/*
+

README.md

+# ISIS3
+Integrated Software for Imagers and Spectrometers ISIS3 public release site