1. Change the initial letter of the comments of the argument from upp…

…ercase to lowercase in Precision.h.

2. Finish document for Precision.h
3. Add Parallel.h in Doxyfile.
4. Complete document for Parallel.h.
5. Add *.swo, *.swn in .gitignore for...

Summary: ...preventing tracking temporary files generated by vim editor.

Test Plan: NA

Reviewers: hmx

Subscribers: zhaohe, YuFande, yhk, xli, wangzhao, shenbo, qiaol, longx17, lisq, Johanli

Differential Revision: http://124.65.131.150:11111/D34

.gitignore

@@ -93,3 +93,5 @@ acs-*.bib
 *.idx
 
 doc/latex
+*.swo
+*.swn

doc/Doxyfile

@@ -797,6 +797,7 @@ INPUT                  = ../include/Geometry/Euler.h \
                          ../include/Geometry/Transformation.h \
                          ../include/CTF.h \
                          ../include/FFT.h \
+                         ../include/Parallel.h \
                          ../include/Image/MRCHeader.h
 
 # This tag can be used to specify the character encoding of the source files