create a packageId in eml prototype
includes a test case to make sure this doesn't overwrite identifiers read in when coercing XML to S4
eml_read gets the namespaces from the file, rather than the default namespaces
updated documentation
update roxygen, avoid error of '@' used in email
remove depricated test
add id get method to read example list
docs
rearrange definitions, depricate and prepare to depricated outdated methods