[COOK-4605] - pecl interaction failures

Use printf instead of echo. See the [echo man page](http://www.unix.com/man-page/POSIX/1posix/echo/), particularly the section:
> If the first operand is -n, or if any of
>	      the operands contain a backslash ( '\' ) character, the results are implementation-
>	      defined.

And there are many implementations. Prior to revision ae23f441cac67ecfcfafcd18f66c0e2844409f5c, you had `echo -e` which, in my shell at least, is used to "enable interpretation of backslash escapes" (like `\r`). Now, I guess, you're just piping "\r" to pecl.

`printf` is posix defined and compliant. Also, fixed the headache I was having outlined in [COOK-4605](https://tickets.opscode.com/browse/COOK-4605).