Bug Report: IndexError when skiprows > 0 and index_col=False
I am using Pandas 0.15.2.  I am trying to read the following space-delimited file, which needs first three lines to be skipped:

```
from pandas import *
tumor_df = read_csv("http://www.stat.columbia.edu/~gelman/book/data/rats.asc", index_col=False, skiprows=3, delim_whitespace=True)
```

However, it results in an IndexError.

```
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-9-b72cfe7f87e1> in <module>()
      3 #tumor_df = read_csv("http://www.stat.columbia.edu/~gelman/book/data/rats.asc", index_col=False, skiprows=3, sep=' ')
      4 #tumor_df = read_csv("rat_tumor.txt", index_col=False, delim_whitespace=True)
----> 5 tumor_df = read_csv("http://www.stat.columbia.edu/~gelman/book/data/rats.asc", index_col=False, skiprows=3, delim_whitespace=True)

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/io/parsers.pyc in parser_f(filepath_or_buffer, sep, dialect, compression, doublequote, escapechar, quotechar, quoting, skipinitialspace, lineterminator, header, index_col, names, prefix, skiprows, skipfooter, skip_footer, na_values, na_fvalues, true_values, false_values, delimiter, converters, dtype, usecols, engine, delim_whitespace, as_recarray, na_filter, compact_ints, use_unsigned, low_memory, buffer_lines, warn_bad_lines, error_bad_lines, keep_default_na, thousands, comment, decimal, parse_dates, keep_date_col, dayfirst, date_parser, memory_map, float_precision, nrows, iterator, chunksize, verbose, encoding, squeeze, mangle_dupe_cols, tupleize_cols, infer_datetime_format, skip_blank_lines)
    463                     skip_blank_lines=skip_blank_lines)
    464 
--> 465         return _read(filepath_or_buffer, kwds)
    466 
    467     parser_f.__name__ = name

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/io/parsers.pyc in _read(filepath_or_buffer, kwds)
    249         return parser
    250 
--> 251     return parser.read()
    252 
    253 _parser_defaults = {

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/io/parsers.pyc in read(self, nrows)
    708                 raise ValueError('skip_footer not supported for iteration')
    709 
--> 710         ret = self._engine.read(nrows)
    711 
    712         if self.options.get('as_recarray'):

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/io/parsers.pyc in read(self, nrows)
   1157 
   1158         try:
-> 1159             data = self._reader.read(nrows)
   1160         except StopIteration:
   1161             if nrows is None:

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/parser.so in pandas.parser.TextReader.read (pandas/parser.c:7396)()

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/parser.so in pandas.parser.TextReader._read_low_memory (pandas/parser.c:7636)()

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/parser.so in pandas.parser.TextReader._read_rows (pandas/parser.c:8474)()

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/parser.so in pandas.parser.TextReader._convert_column_data (pandas/parser.c:9485)()

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/parser.so in pandas.parser.TextReader._get_column_name (pandas/parser.c:13179)()

IndexError: list index out of range
```

When I removed first three lines and did not use skiprows argument, read_csv() worked fine.

This is my first time submitting a bug report, so I apologize for your inconvenience if this deviates from the convention.
