Removed exception from CompilerHandler constructor
Throwing an exception if "codebender_object_files" directory could not be created in
the contructor would not handle all the cases, so it had to be replaced.
Remove arduino skeleton from preprocessing procedure
Until now, the contents of a skeleton file (usually main.cpp) was included in
the first lines of the .ino file and then,the skeleton file was excluded from the list of
core objects, before compiling them. From now on, only Arduino.h is included to the .ino file
and the main.cpp skeleton file is compiled along with the other core files, and then linked to the
output file.