Numpy support / recipe

The toolchain got few adjustement to allow the compilation of Numpy and the execution on the device:

- It requires unittest in the Python distribution. It was deleted
(fixed in `tools/reduce-python.sh`)
- It requires future_builtins (added in `src/ModuleSetup`)
- Deduplication of symbols now can merge multiple .a for easier
management in Xcode (`tools/environments.sh`)
- We avoid passing linker parameters to ar (`-Wl` ignored in
`tools/liblink`).

Numpy itself is patched to:

- force endianess to be little, using directly `endian.h` leads to
detection error during the build process.
- force not BLAS to be built, we use the Accelerate framework instead
- rework the dependencies relation for lapack_lite and _umath_linalg,
to prevent duplicate symbols and force compilation of necessary module
/ missing symbols.

---

The compilation process is:

1. Compile the toolchain with `tools/build-all.sh`
2. Compile Numpy with `tools/build-numpy.sh`
3. Create a project with `tools/xcode-create-project.sh`
4. In your Xcode project, click on your project, go to `Build Phases`, open the `Link Binary With Libraries`, click on the `+` at the end of the list and add the `kivy-ios/build/lib/libnumpy.a`.
5. Repeat the 4. operation and add the Accelerate Framework

Done !

---

Here is the test i runned on an iPad 3 / iOS 7.1 (i've lowered the Deployement Target to 7.1 in the project):

```
from numpy import *
a = arange(12)
print a
a = a.reshape(3,2,2)
print a

print "--> test linalg"
import numpy as np
a = np.array([[3,1], [1,2]])
b = np.array([9,8])
x = np.linalg.solve(a, b)
print "x is", x
print "is the solution is correct?", np.allclose(np.dot(a, x), b)
```

The output on the device is:
```
2014-11-24 03:24:15.419 testnumpy[841:60b] PythonHome is: /var/mobile/Applications/D4755AD6-213F-49A9-B600-5D5E7BDBF2A1/testnumpy.app
2014-11-24 03:24:15.427 testnumpy[841:60b] Initializing python
2014-11-24 03:24:15.699 testnumpy[841:60b] Running main.pyo: /var/mobile/Applications/D4755AD6-213F-49A9-B600-5D5E7BDBF2A1/testnumpy.app/YourApp/main.pyo
[ 0  1  2  3  4  5  6  7  8  9 10 11]
[[[ 0  1]
  [ 2  3]]

 [[ 4  5]
  [ 6  7]]

 [[ 8  9]
  [10 11]]]
--> test linalg
x is [ 2.  3.]
is the solution is correct? True
2014-11-24 03:24:16.407 testnumpy[841:60b] Leaving
```
---

Original issue ref: kivy/kivy#1161
Related bounty: https://www.bountysource.com/issues/305883-numpy-for-kivy-ios