title: SIGSEGV backtrace with libc is repeating entries
body: <p>I was using libunwind prior to moving to the available execinfo backtrace. After implementing a new backtrace I was enjoying it until I removed the libunwind from the project and did a full rebuild. </p>
  
  <p>Now my backtrace function refuses to produce a normal result from the SIGSEGV ( I know its not safe to do the backtrace from there ), but why was it working fine before? </p>
  
  <p>I will post the output for now with incorrect results. First backtrace is an exception, second, deliberate SIGSEGV - the expected result would be a trace to the __libc_start_main</p>
  
  <p>I remember I read something about signal stacking as problem?</p>
  
  <pre><code>ERROR: FatalException detected: Unable to find string Id STR_PATIENT_LIST in configuration xml file at gui.cpp +1224
  ===========================================
  FATAL STACK BACKTRACE
  [bt]: (1 ) [0x1aed350]
  [bt]: (2 ) ./ambusergm(getStrIdElement(char const*)+0x1a4) [0xa3d6c]
  [bt]: (3 ) ./ambusergm(getCurrentLanguageStr(char const*)+0x18) [0xa4968]
  [bt]: (4 ) ./ambusergm(createDialogs+0x70) [0xa4ce4]
  [bt]: (5 ) ./ambusergm(handleMenuUniqueIdEvent+0x1278) [0x90030]
  [bt]: (6 ) ./ambusergm(menuSelectionInvoke(int, int)+0x278) [0xa14ac]
  [bt]: (7 ) ./ambusergm(reloadMenu+0xe0) [0xab51c]
  [bt]: (8 ) ./ambusergm(main+0x638) [0x600b0]
  [bt]: (9 ) /lib/libc.so.6(__libc_start_main+0x120) [0x402f7fd4]
  ===========================================
  
  signal 11 (Segmentation fault), address is (nil) from 0x166398
  ===========================================
  CRASH STACK BACKTRACE
  [bt]: (1 ) ./ambusergm(MessageBoxDlg::Setup(MessageBoxType, int, int, int, int, wchar_t const*, wchar_t const*)+0x10) [0x166398]
  [bt]: (2 ) /lib/libc.so.6(__default_rt_sa_restorer_v2+0) [0x4030e630]
  [bt]: (3 ) ./ambusergm(MessageBoxDlg::Setup(MessageBoxType, int, int, int, int, wchar_t const*, wchar_t const*)+0x10) [0x166398]
  
  ... repeated to the last entry
  
  [bt]: (49) ./ambusergm(MessageBoxDlg::Setup(MessageBoxType, int, int, int, int, wchar_t const*, wchar_t const*)+0x10) [0x166398]
  ===========================================
  </code></pre>