This patch adds a context menu to variables in the debugger variable
tree view that has an option to set the value of a variable. An input
box will pop up asking for the new value of the variable, which
is then parsed and used to set the actual variable.
.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
