Update tweep.py

Tweep.py would generate an error on -g option if used as unique argument.

Update READ.ME

add explantion for -g option

Added a -g option for geocoded tweets

- Fixed check and error handling. Moved them to seperate functions to be more organized.
- Added userid search
- Added Tweet limit (Pulls tweets in incriments of 20- i can't modify that).
- Added counter (Display number of tweets collected at the end.)

I propose this patch that adds the -g option.

Use it like : 

python3 tweep.py -g 48.880048,2.385939,1km

Could be enhanced, though.

Fixed Spacing bug

add hashtags extraction and cleanse text (urls)

Made hashtag display indicated by arg rather than being displayed by default.

I added an automatic extraction for hashtags, and a space character before http, https and pic urls in the text column, in order to parse it more conveniently.