Labedf

set pre-splitting mean and std to attributes of each dataset (edf2.split_annotations_edf2hdf) 16ad99c1f66f147118325d1ec4cb0716f0776368

[add split_signals_func option (edf2.split_annotations_edf2hdf)](https://github.com/s-n-1-0/labedf.py/commit/a5a62bcb74073d2916e1769cdd9b1b45ae8db125)
*the signal length can be changed by preprocessing.

+ rename before_preprocessing_func -> before_preprocessing_func (edf2.split_annotations_edf2hdf)
+ revert preprocessing_annsignals_func -> after_preprocessing_func (edf2.split_annotations_edf2hdf)

b1549ea50530dcba1af86ebb0dae621cfa49316e

Changes
+ add preprocessing function option
+ [add preprocessing function option (csv2.merge_csv2edf)](https://github.com/s-n-1-0/labedf.py/commit/cd986ee6be1d8a19912ce1d3792cab1687efd58a)
+ [add preprocessing function option (edf2.split_annotations_edf2hdf)](https://github.com/s-n-1-0/labedf.py/commit/d3bb4b341002d185725148fa92ee9447dfd577fd)

Changes
Major Changes
+ [add function to split edf by annotations (edf2.split_annotations_edf2hdf)](https://github.com/s-n-1-0/labedf.py/commit/97a456aad28d6e81fd7667262345de0ea205036e)
+ [fix to consider sync_marker_name when merging (csv2.merge_csv2edf)](https://github.com/s-n-1-0/labedf.py/commit/9e6eb3899c33b86a5292043f54eee33746914565)
+ sync lag support
Minor Changes
+ [add option to remove annotation of marker end time](https://github.com/s-n-1-0/labedf.py/commit/f280412dfb695a7d651c5b13f1af7f579fe959b6)
+ [changed to write labels to hdf file attributes](https://github.com/s-n-1-0/labedf.py/commit/0bb0f0469af2185a3e2de8c23362460ca6d181e9)
+ [rename output_path -> export_path (merge_csv2edf arg)](https://github.com/s-n-1-0/labedf.py/commit/3e2b4fd8b96b53470ebedb770c7f584901b78cf7)
+ [Change the version of labcsv -> v1.0.3](https://github.com/s-n-1-0/labedf.py/commit/566a78637d5975260380678004f4741086e8ec08)

first version.