This CL a logical revert of a previous CL [1], which separated Java
files into common ones and overridable ones.  Now that that overriding
concept is no longer used, there is no need to keep having separate
directory structure.

 [1]: Ic734bd4d20aa050c688a3158b1a382ae0ac18991
      fb74ab15

Fix: 79323502
Test: make -j aosp_taimen-userdebug && make -j
Test: tapas LatinIME && make -j
Change-Id: I2090bc25d18e6d4f24e91c2cbfe832755cbb4e8f

Change-Id: I82d5a17a5ec96f26047d29e79f3f28850fc5b3bb

This CL also adds @SuppressWarning("unused" to java-overridable package.

Bug: 18003991
Change-Id: If70527e30654384705d7a814f5efd181d9f539e1

We used to have separate methods for existence of dicts
according to whether it's a file or a resource. This unifies both.

Bug: 11230254
Bug: 17979623
Change-Id: I728773461f3465f756d06297c3f3bee34390c3e6

...or more exactly, the script of the keyboard layout set associated
with a given subtype.

Bug: 11230254
Change-Id: I82f5fc81ecffc561781816008c853be6ff9438dd

The code would iterate all enabled subtypes each time
getCurrentSubtype() is called, which is really quite frequent.

Bug: 11230254
Change-Id: I91feb36de6eca84967e848fc585aae04b350be89

Bug: 11230254
Change-Id: I9bc19db5f101eeb6841394fe3637f271c93cbfa7

Bug: 11230254
Change-Id: I7b60d9174d7d267eb1b3cd848cff36cdbea75b12

Bug: 11230254
Change-Id: I15d42fad155142fa6f556f13e84cad489be00dbd

This should make IDEs happy with appropriate source code directory
selection.

Change-Id: Ic734bd4d20aa050c688a3158b1a382ae0ac18991
(cherry picked from commit fb74ab15)

This should make IDEs happy with appropriate source code directory
selection.

bug: 16829244
Change-Id: Ic734bd4d20aa050c688a3158b1a382ae0ac18991

This fixes null pointer exceptions that are caused when
getSuggestion() is called from spell checker.

Change-Id: Ifc9e7abb900e1a4646e33c91022effde439673e4

Change-Id: Id170dbfe2dcfc93130b7be4a84615940403ec37f

Change-Id: I1c5b27c8edf231680edb8d96f63b9d04cfc6a6fa

Change-Id: I9fec0c03b7da9ce0305b494193f4cfe3fca144f3