Fixed seg fault cause by improper access of memory in read_cuetext() whe...

...n checking for an ASCII_LF while length is 0. Modified the string_getline() function in order to retain the newline characters. This solved a problem when the parser needs to check for the newline characters in order to determine whether or not it is finished a cue.

Issue: #6

**Builds On  Top Of**
Issue: #11 

**Note:** 
* 2012/01/24: They're are still a few tests failing in the unit test. One due to another seg-fault and the rest due to there ASSERTS on error count being wrong. 
* 2012/01/25: Including @rillian XFail fixes has exposed a huge number of exceptions and seg faults. I'll try to address these asap.