code style
MR for parsing all data for snow cumulation

parse precipitation, snowdepth, date,
implementation of SnowFallEstimation (still buggy)
fix bug with substring search
avoid emitting key/value when not snowing
fix string comparison + improve key emission

- use s.indexOf("substring") != -1 to know if "substring" happens in s.
(s.contains is not meant for that)
- fix bug that causes no key/val to be emited if there was non-snow
precipitation, even if there was snow-depth data
fix bug with snow cumulation from snow depth
fix mapper: value output were missing

- fix temperature/snowDepth/cumulation were always "**"
fix conversion rain to snow
fix bug and more testing

fix bug (missing .java for SnowData file)
more testing: everything seems ok.
exclude values with 9999 (=missing value)
fix erroneous date reading
more testing + some code cleaning
Fix SnowData output when data = **

fix: it should output NO_SNOW_DATA instead of 0 or -1
Rename SnowFallEstimation to DailySnowFallEstimation

This is more clear as it output daily estimation and weekly/monthly/etc
estimation can easily be made from its output.
Add weeklySnowFall
Add SnowFall.java
Add DailyToWeeklySnowFallEstimation.ava
remove latitude and longitude from output
increase num of Map/Reduce tasks