Merge pull request #5 from USGS-R/master

update changes
Merge pull request #16 from ldecicco-USGS/master

Updated functions to new dataRetrieval naming convention.
Merge pull request #17 from ldecicco-USGS/master

Fixed a character bug.
Merge pull request #18 from ldecicco-USGS/master

Took out re-order. Let user deal with that.
Merge pull request #19 from schristel-USGS/master

Merge pull request #5 from USGS-R/master
Added multiCor function and data for example (dfOptical)
Merge branch 'master' of github.com:USGS-R/USGSHydroTools
Added plotHydroConc function
HydroVol revisions: added a step to assure that the Q file is in chronological order, and a step to assign NA for results where the starting/ending dates and times are missing in the df.dates dataframe
Merge pull request #6 from USGS-R/master

update changes
changed how column is reference so it is applicable to all user defined df.dates
Merge pull request #20 from schristel-USGS/master

Merge pull request #6 from USGS-R/master
modified loadCompEvent function to handle periods with only one sample and added a column in the return dataframe to indicate how many samples there were for each event.

Changed a comment in plotHydroConc
modified WQcompos to use begin and end dates and times for all samples in the final df. Also added a "codes" option to paste lab IDs together for a combined lab ID that reflects all samples included in the overall composite sample.
Merge pull request #21 from srcorsi-USGS/master

Steve's stuff.
Brought examples within 100 character per line limit.
Renamed licesnse.
Updating version, date, and dependencies.