BUG: Running past end of buffer and leak

ifstream::read does not terminate the buffer with null. The while loop
was running past the end of the buffer. This patch appends a null
before processing the string.

The buffer was allocated but never freed.

Change-Id: I9bedd7c7825424547ad4892d7ae2348ce0379d19
Merge topic 'InvalidRead_MultiNewickTreeReader' into master

76f1697a BUG: Running past end of buffer and leak