Add tip to README for Cygwin users

Bash scripts will throw errors complaining about line breaks when
running in Cygwin without change to EOL behaviour.
Correct usage information

Usage will get printed as
```
sendMessages.sh -t 61412345678 -m Hi there
```
ie. without the quotes
Update Usage info to include --delivery-report option

Update Usage info to include --delivery-report option
add delivery report to usage example

add --delivery-report to usage example
Merge pull request #1 from jetyliu727/master

Merge @jetyliu727's delivery-report usage and Cygwin notes.