Enabled sampler arrays in shader

Enabled sampler arrays in shader

Previously, texture units were only bound to the first
element of any sampler array.

Modified the shader reflection parser to find sampler arrays
of the format
  uniform sampler2D mySamplers[16]

and store the number of elements in the sampler code.

Modified the binding code to ensure that textures are bound
to each element of a sampler array.

Made several assumptions in this code:
A) that GL returns sequential locations for each uniform array element
(It doesn't guarantee a strict sequence, but in practice, this is the
case).

B) that the dali-core implementation binds texture units in the order 0..N-1
with a binding index of 0..N-1. (A safe assumption, given we know how
dali-core works!)

Note, we don't really use locations for non-sampler uniform array elements,
either, we just offset from the first location.

Change-Id: I68c61f3e22303271d5d916c3588f4a3bd5898757
Signed-off-by: David Steele <david.steele@samsung.com>