Specify per-file CSV options in URL fragments

- FROM <file.csv#encoding=utf-8> to specify encoding
- FROM <file.csv#header=present> to indicate column names in first row
- FROM <file.csv#key1=value1;key2=value2> for multiple options
- Also works in file names on the command line
Add --delimiter, --tabs, --escapechar, --quotechar (#5)
Configure CSV syntax via pseudo-fragments

- file.csv#delimiter=tab
- file.csv#quotechar=singlequote
- file.csv#escapechar=backslash
- Supported in FROM clause and on command line
- Also supports syntax such as delimiter=%09 or delimiter=,