power.py detailed output is mis-aligned and has poor spacing

[chris-ashe]

The output for the detailed power balance in the OUT.DAT file is currently disorganised and unaligned with random line breaks represented by O's.
The fault is seen around line 1323 in power.py

Power Balance for Reactor (across vacuum vessel boundary) - Detail
 ------------------------------------------------------------------
 
 High-grade             Low-grade              Total
 thermal power (MW)     thermal power (MW)      (MW)
 First wall:
 pnucfw                                                                         0.00                   0.00
 palpfwmw                                                                       0.00                    0.00
 pradfw                                                                         0.00                   0.00
 htpmw_fw                                                                       0.00                     0.00
 
 Blanket:
 pnucblkt                                                                       0.00                   0.00
 0.0e0 0.0e0 0.0e0
 0.0e0 0.0e0 0.0e0
 htpmw_blkt                                                                     0.00                     0.00
 
 Shield:
 0.1e-08 0.0 0.1e-08
 0.0e0 0.0e0 0.0e0
 0.0e0 0.0e0 0.0e0
 1. 0.0 1.1

More problems are seen further down in the output from the example above