Merge pull request #4 from coherentsolutions/master

disable interrupts during flash erase/writes
update so we can use the new intelhex 1.5

this requires the new padding option of the IntelHex object to be used
rather than the older pad option of the tobinstr() method (note the pad
option still works but will be depreciated, and a warning is printed
that gets into the final hex output because of our redirection)
Merge pull request #1 from othane/master

update to intelhex 1.5