Gaiaxpy

Cosmos credentials are optional when using lists and queries.

Query official Gaia Archive.
Updated Hipparcos-Tycho bases.
Added fix for single band source with lists and queries.
Added error correction tables for Gaia_DR3_Vega, Els_Custom_W09_S2, Pristine and Sky_Mapper.
Fixed bug in error correction caused when a regular system and its standardised version were requested on the same data frame.

Fix error correction bug in system HST_ACSWFC.
Fix error when passing a single PhotometricSystem to error correction.
Add SkyMapper filter.
Add Windows compatibility.

Patch missing headers file for ECSV in MANIFEST.

Patch missing headers file for ECSV in MANIFEST.

Initial release.