Support double quotation in Path and optimize the Path String

[Boris Zhu]

Hi
I write a pr about using the detached full path instead of the full path
between SQL analysis and metadata in order to reduce unnecessary path
split. A new Class extends Path which is called “PartialPath” which
contains the detached full path. BTW, you can use double quotes in name of
device. here is the pr, https://github.com/apache/incubator-iotdb/pull/1627