HUE-2138 [search] Slider widget UX

Added viewModel update on blur and slideStop
HUE-2138 [search] Slider widget UX

Allow 0 value
[core] Shrink char field max length

This fixes Oracle issues with the default charset: AL16UTF16.
Max byte length of NVARCHAR2 type is 4000. 2047 characters
would consume 4094 bytes of space. We should support
up to 4 byte charsets. So bringing the length of these fields
down to 1000 => 4000 maximum bytes consumed.
[doc] Update README to propose a compatible maven

"make apps" fails with errors using maven2 package.
It works fine if we use maven3 (default maven package on Ubuntu).
HUE-2190 [search] Truncate function doesn't work anymore

Fixed triple escaping for functions
HUE-2184 [core] Connect to Oracle via Service Name
HUE-2188 [beeswax] Remove Email me on completion
HUE-2189 [search] Exporting results should not add extra HTML
[libsolr] Security impersonation for all the API operations
HUE-2177 [impala] DB assist should support zero databases
HUE-2178 [core] Refactor and extract as a lib search charts

Extracted js and css to desktop
Created common_dashboard for importing all the necessary things
HUE-2196 [beeswax] Explain doesn't account for Hive settings
HUE-2193 [beeswax] HiveServer2 pass-through LDAP authentication at thrift level
HUE-2193 [beeswax] Updates the tests for HiveServer2 LDAP
HUE-2192 [core] Create parameter to choose LDAP username for HS2
[core] Support Resource Manager HA active / standby switching

Used to only failover when the RM was going down.
Invalidate the current RM API when switching RM.
HUE-2178 [core] Refactor and extract as a lib search layout

Extracted common column, row and widget js
Moved basic toolbar and skeleton layout to common dashboard
HUE-2122 [impala] Smarter db and table cache

Cached the db list too
Bumped cached time expiration to 7 days
[metastore] Support of UTF-8 in the comments and names of tables

if value.contains(chinese):
    print "'ascii' codec can't decode byte 0xe4 in position 0: ordinal not in range(128)"
HUE-2076 [core] Create retina icons/logos

Retinified all the logos and images