Reads the feature termIndex from the specified input stream.
This method processes input in terms of lines. A natural
line of input is terminated either by a set of line
terminator characters (\n or \r or \r\n) or by the end
of the file. A natural line may be either a blank line,
a comment line, or hold some part of a id-feature pair.
Lines are read from the input stream until end of file
is reached.
A natural line that contains only white space characters
is considered blank and is ignored. A comment line has
an ASCII '#' as its first non-white space character;
comment lines are also ignored and do not encode id-feature
information.
The id contains all of the characters in the line starting
with the first non-white space character and up to, but
not including, the first '\t'. All remaining characters
on the line become part of the associated feature string;
if there are no remaining characters, the feature is the
empty string "".