* Update AppController.java

modify /apps/search -> /apps/search/by

* Update directive.js

modify /apps/search -> /apps/search/by

* Update AppController.java

modify apps/search -> apps/by-appId-or-name

* Update directive.js

modify /apps/search -> /apps/search/by-appId-or-name

* Update AppController.java

modify /apps/search -> /apps/search/by-appId-or-name

fix #2768 that the namespace length is mis-calculated for private namespaces and public namespaces which don't need to append prefix (#2784)

修改应用appid显示为部门的问题

* fix #2092.

* fix #2092.

* change to Integer.compare.

* code clean.

* code clean.

This reverts commit 235a5228.

* fix #2092.

* Revert "fix #2092."

This reverts commit d8076ef2

* fix #2092. change deferredResults key toLowerCase.

* change HashMap to TreeMap.

* add DeferredResultWrapper compareTo;

* Bugfix: fix miscellaneous bugs and polish code

* Update EmbeddedApollo.java

Objects.isNull is only available from jdk 1.8 but apollo-client is targeted to jdk 1.7+, so we need to use a compatible one (#2677)

fix delete children clusters twice.

* fix setting value of property in xml is null throws NullPointerException

* fix setting null value of property in xml throws NullPointerException

This reverts commit 437026f3.

* init i18n support

* polish translations and fix some bugs introduced

* refactor app namespace duplicate message

* fix non-properties namespace display issue