umb.hrl: more constants from docs
umb_frame: added methods for coding floats
umb_request: new methods

Added:
* methods to obtain info about channels;
* decoding types;
* advanced decoding of some channels (e.g. precipation type channel).
umb_transport: infinity timeout to (dis)connects.
umb_transport_tcp: correctly handle closed sockets
gitignore: added escriptized umb