Fix/http upload

[ghost]

Removed never used strings:

• http_http "http://"
• http_200 "200 "
• http_301 "301 "
• http_302 "302 "
• http_content_type "content-type: "
• http_texthtml "text/html"
• http_location "location: "
• http_host "host: "
• http_crnl "\r\n"
• http_referer "Referer:"
• http_text ".txt"
• http_content_type_binary "Content-type: application/octet-stream\r\n\r\n"

Removed useless extension

• http_shtml ".shtml"

Add an header sent with all requests

• http_header_all "Server: uIP/1.0\r\nConnection: close\r\nAccess-Control-Allow-Origin: *\r\n"