docs: rewrite .iloc accessing beyond ends.

Let's actually talk about what the current behaviour is, not what the
behaviour used to be.
Merge pull request #7756 from lexual/indexing_docs_past_end

docs: rewrite .iloc accessing beyond ends.
BUG: DatetimeIndex.__iter__ creates a temp array of Timestamp (GH7683)

PERF: DatetimeIndex.__iter__ now uses ints_to_pydatetime with boxing

tslib: remove code dup in ints_to_pydatetime

PERF: add inline to create_timestamp_from_*
Merge pull request #7720 from jreback/iter

PERF: improve perf of index iteration (GH7683)
ENH: Add uint and bool support in to_stata

Added support for uint (uint8, uint16 and uint32, but not uint64) and bool
datatypes in to_stata.   Added an explanation of supported data types in io.rst.
closes #7097 and closes #7365
Merge pull request #7767 from lexual/remove_multi_index_bleeding_edge_comment

Docs: MultiIndex support is hardly bleeding edge, remove docs warnings.
Closes #7758 - astype(unicode) returning unicode.

Just calls numpy.unicode on all the values.
Seems to work alright on python2 and python3.

Added bugfix of #7758 to v0.15.0 changelog.