AStyle: options update

This should reflect these rules that we have defined since mbed 2:

```
Indentation - 4 spaces. Please do not use tabs.
Braces - K&R (see the exception 1 TBS below)
1 TBS -use braces for statements if, else, while, for (exception from K&R) Reference: http://en.wikipedia.org/wiki/Indent_style#Variant:_1TBS
One line per statement
Preprocessor macro starts at the beginning of a new line, the code inside is indented accordingly the code above it
Cases within switch are indented (exception from K&R)
Space after statements if, while, for, switch, same applies to binary and ternary operators
Each line has preferably at most 120 characters
For pointers, '*' is adjacent to a data name (analogin_t *obj) or a function name (analog_t *get_analogin_object())
Don't leave trailing spaces at the end of lines
Empty lines should have no trailing spaces
Unix line endings are default option for files
Use capital letters for macros
A file should have an empty line at the end
```

.astylerc

@@ -10,16 +10,14 @@ style=kr
 # Use -j as it was changed in astyle from brackets to braces, this way it is compatible with older astyle versions
 -j
 
-# 4 spaces, no tabs
+# 4 spaces, convert tabs to spaces
 indent=spaces=4
 convert-tabs
 
+# Indent switches and cases
 indent-switches
 indent-cases
 
-# Comments should be indented
-indent-col1-comments
-
 # Remove spaces in and around parentheses
 unpad-paren
 
@@ -31,12 +29,6 @@ pad-oper
 align-pointer=name
 align-reference=name
 
-# Attach { to the classes and namespaces
+# Attach { for classes and namespaces
 attach-namespaces
 attach-classes
-
-# add braces to one liners
-add-braces
-
-# Don't limit spaces in a continous statement (default is 40)
-max-instatement-indent=120