GitLab

* added new aliases for regression_l2 to docs

* fixed new line

* fixed tweedie_variance_power description

* moved gamma and tweedie metrics to other regression metrics

* added new aliases for l2 to docs

* added new alias for l1 to docs

* added new alias for log loss to docs

* added new aliases for multiclass to docs

* added description for default value of metric param

* fixed link to poisson regression and capitalized regressions' names

* removed unused earlier alias type for gamma deviance

* added aliases for multiclass and multiclass_ova

* updated Quick-Start.rst according to Parameters.rst

* added cross-entropy into Features

* added aliases

* unfinished

* some refines.

* fix a bug

* some refines

* remove useless files

* some small fixes

* clean code

* clean code

* fix connect

* fix a broken link

* fix a broken link

* update network.h

Improve training speed in parallel learning where workers is not powers of 2

* update linders_socket.cpp

Improve training speed in parallel learning where workers is not powers of 2

* update linder_topo.cpp

Improve training speed in parallel learning where workers is not powers of 2

* update network.cpp

Improve training speed in parallel learning where workers is not powers of 2

* update linder_topo.cpp

fix a bug

* refine allgather.

* fix a bug.

* add code for refit tree

* add implementation.

* update documents.

* clean code

* fix a type

* fix feature fraction

* fix bugs.