Improving methods(+) doctest

The `methods(+)` doctest seems to fail periodically due to the order
of the methods changing. It appears that blocks of these methods
typically stick together so I picked a nice reading block and attempted
to format with the least amount of ellipsis.

Here is an interesting failure which caused me to update the layout
of the doctest. Before this commit we used the following as a doctest:

```jldoctest
julia> methods(+)
 # 166 methods for generic function "+":
...
+(a::Float16, b::Float16) at float16.jl:136...
+(x::Float32, y::Float32) at float.jl:206...
+(x::Float64, y::Float64) at float.jl:207...
+(x::Bool, z::Complex{Bool}) at complex.jl:137...
+(x::Bool, y::Bool) at bool.jl:36...
+(x::Bool) at bool.jl:33...
+{T<:AbstractFloat}(x::Bool, y::T) at bool.jl:43...
+(x::Bool, z::Complex) at complex.jl:144...
+(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:105...
+(x::Char, y::Integer) at char.jl:40
...
+(a, b, c, xs...) at operators.jl:119
```

The output was as follows:
```
 # 166 methods for generic function "+":
+(a::Float16, b::Float16) at float16.jl:136
+(x::Float32, y::Float32) at float.jl:206
+(x::Float64, y::Float64) at float.jl:207
+(x::Bool, z::Complex{Bool}) at complex.jl:137
+(x::Bool, y::Bool) at bool.jl:36
+(x::Bool) at bool.jl:33
+{T<:AbstractFloat}(x::Bool, y::T) at bool.jl:43
+(x::Bool, z::Complex) at complex.jl:144
+(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:105
+(x::Char, y::Integer) at char.jl:40
...
+(a, b, c, xs...) at operators.jl:119
```

doc/manual/methods.rst

@@ -234,17 +234,16 @@ Julia language. Core operations typically have dozens of methods:
 .. doctest::
 
     julia> methods(+)
-    # 166 methods for generic function "+":
-    ...
-    +(a::Float16, b::Float16) at float16.jl:136...
-    +(x::Float32, y::Float32) at float.jl:206...
-    +(x::Float64, y::Float64) at float.jl:207...
-    +(x::Bool, z::Complex{Bool}) at complex.jl:137...
-    +(x::Bool, y::Bool) at bool.jl:36...
-    +(x::Bool) at bool.jl:33...
-    +{T<:AbstractFloat}(x::Bool, y::T) at bool.jl:43...
-    +(x::Bool, z::Complex) at complex.jl:144...
-    +(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:105...
+    # 166 methods for generic function "+":...
+    +(a::Float16, b::Float16) at float16.jl:136
+    +(x::Float32, y::Float32) at float.jl:206
+    +(x::Float64, y::Float64) at float.jl:207
+    +(x::Bool, z::Complex{Bool}) at complex.jl:137
+    +(x::Bool, y::Bool) at bool.jl:36
+    +(x::Bool) at bool.jl:33
+    +{T<:AbstractFloat}(x::Bool, y::T) at bool.jl:43
+    +(x::Bool, z::Complex) at complex.jl:144
+    +(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:105
     +(x::Char, y::Integer) at char.jl:40
     ...
     +(a, b, c, xs...) at operators.jl:119