Added missing messages in es_es. Closes #1

Please note: the spanish translation for 'Gutter' can be either 'medianil' or 'calle'. I've used the first as it is technically more correct, even if it sounds a bit more strange than the latter.
add off, on, snap to pixels
whitespace
clear form
fix broken messages
update asset
ignore everything except the main file
try ignoring this way
devdeps
Update error text
be a bit more verbose about the error
add travis config
copy tweak
Definitely nope
Update pt_br translations for 3.1.0