os tests

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[os] use cp() in cptree() and update_tree()

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[sys] command_line_options()

command_line_options() generates array of options corresponding to unix
conventions from javascript options array

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>
[os] cp: option hardlink

Signed-off-by: Denis Zalevskiy <denis.zalevskiy@jolla.com>