ARROW-357: Use a single RowGroup for Parquet files as default.

This is not the optimal choice, we should rather have an option to optimise for the underlying block size of the filesystem but without the infrastructure for that in ``parquet-cpp``, writing a single RowGroup is the much better choice.

Author: Uwe L. Korn <uwelk@xhochy.com>

Closes #192 from xhochy/ARROW-357 and squashes the following commits:

9eccefd [Uwe L. Korn] ARROW-357: Use a single RowGroup for Parquet files as default.

Author: xhochy

python/pyarrow/parquet.pyx

@@ -106,7 +106,8 @@ def write_table(table, filename, chunk_size=None, version=None,
     table : pyarrow.Table
     filename : string
     chunk_size : int
-        The maximum number of rows in each Parquet RowGroup
+        The maximum number of rows in each Parquet RowGroup. As a default,
+        we will write a single RowGroup per file.
     version : {"1.0", "2.0"}, default "1.0"
         The Parquet format version, defaults to 1.0
     use_dictionary : bool or list
@@ -121,7 +122,7 @@ def write_table(table, filename, chunk_size=None, version=None,
     cdef WriterProperties.Builder properties_builder
     cdef int64_t chunk_size_ = 0
     if chunk_size is None:
-        chunk_size_ = min(ctable_.num_rows(), int(2**16))
+        chunk_size_ = ctable_.num_rows()
     else:
         chunk_size_ = chunk_size