typo fix
Get mime type from download, if download is a file name

Get mime type from the download parameter instead of from the file, if
download is a file name
fixed typo in doc
fix typo tutorial grammatical corrections
Merge pull request #679 from avelino/tutorial_grammatical_corrections

fix typo tutorial grammatical corrections
Merge pull request #677 from jhargis/typo_fix_625

fixed typo in doc
Merge pull request #673 from jeorgen/mimetype_from_download

Get mime type from download, if download is a file name
Merge pull request #669 from zvxr/master

typo fix
fix status code 413 description as RFC2616
10.4.14 413 Request Entity Too Large ............................69
https://www.ietf.org/rfc/rfc2616.txt
Merge pull request #681 from avelino/413_description_RFC2616

fix status code 413 description as RFC2616