Breakpad symbol dumper: Move Linux dumping classes into src/common.

The Linux symbol dumper's classes are reasonably portable, and should be
usable for the Mac dumper as well. Move them to src/common, along with
their unit tests. Update #include directives and Makefile.

a=jimblandy, r=nealsid


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@567 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/common/testdata/stabs_reader_unittest.input1

@@ -0,0 +1,19 @@
+SO      10   11   0x02 builddir/
+FUN     20   21   0x12 not the SO with source file name we expected 
+SO      30   31   0x22 
+SO      40   41   0x32 builddir1/
+SO      50   51   0x42 file1.c
+LSYM    60   61   0x52 not the FUN we're looking for
+FUN     70   71   0x62 fun1
+BINCL   80   81   0x72 something to ignore in a FUN body
+SLINE   90   91   0x82
+SOL    100  101   0x92 header.h
+SLINE  110  111  0x102
+FUN    120  121  0x112 fun2:some stabs type info here, to trim from the name
+SLINE  130  131  0x122
+SOL    140  141  0x132 file1.c
+SLINE  150  151  0x142
+SO     160  161  0x152
+LSYM   170  171  0x162
+SO     180  181  0x182 file3.c
+SO     190  191  0x192